Connecting Resistors questions

Three resistors are connected in parallel. If the resistance of one of them is one ohm, the equivalent resistance of these resistors is ..........

1. A less than one ohm
2. B greater than one ohm
3. C equal to one ohm
4. D cannot be found without knowing the two unknown resistances

Three resistors of 120 Ω, 60 Ω and 40 Ω. Their total resistance when connected:
in series is ..........

1. A 520 Ω
2. B 220 Ω
3. C 110 Ω
4. D 34 Ω

Three resistors of 120 Ω, 60 Ω and 40 Ω. Their total resistance when connected:
in parallel is ..........

1. A 10 Ω
2. B 20 Ω
3. C 30 Ω
4. D 40 Ω

Which of the following statements is correct for the opposite electric circuit?

1. A $R_2$ and $R_3$ are connected in series
2. B $R_1$ and $R_3$ are connected in parallel
3. C $R_4$ and $R_5$ are connected in parallel
4. D $R_1$ and $R_2$ are connected in parallel

You have three resistors of 3 Ω each, connected in four different ways (a), (b), (c), (d) as in the following figures. The way of connection in which the equivalent resistance is:
4.5 Ω is ..........

1. A (a)
2. B (b)
3. C (c)
4. D (d)

You have three resistors of 3 Ω each, connected in four different ways (a), (b), (c), (d) as in the following figures. The way of connection in which the equivalent resistance is:
2 Ω is ..........

1. A (a)
2. B (b)
3. C (c)
4. D (d)

You have three resistors of 3 Ω each, connected in four different ways (a), (b), (c), (d) as in the following figures. The way of connection in which the equivalent resistance is:
1 Ω is ..........

1. A (a)
2. B (b)
3. C (c)
4. D (d)

The opposite figure represents part of an electric circuit. Removing which resistor(s) from the circuit increases the equivalent resistance?

1. A $R_1$
2. B $R_2$
3. C $R_4$
4. D $R_1$, $R_2$, $R_3$

In the opposite figure, the equivalent resistance between points a and b is ..........

1. A 15 Ω
2. B 16 Ω
3. C 17 Ω
4. D 18 Ω

In the opposite figure, the equivalent resistance between points a and b is ..........

1. A 1 Ω
2. B 1.5 Ω
3. C 2 Ω
4. D 2.5 Ω

In the opposite figure, the equivalent resistance between points a and b is ..........

1. A 15 Ω
2. B 21 Ω
3. C 24 Ω
4. D 30 Ω

In the opposite figure, the equivalent resistance between points a and b is ..........

1. A 5 Ω
2. B 10 Ω
3. C 15 Ω
4. D 20 Ω

In the opposite figure, the equivalent resistance between points a and b is ..........

1. A 2.5 Ω
2. B 5 Ω
3. C 7.5 Ω
4. D 10 Ω

In the opposite figure, the equivalent resistance between points a and b is ..........

1. A 2 Ω
2. B 4 Ω
3. C 6 Ω
4. D 8 Ω

In the opposite figure, the equivalent resistance between points a and b is ..........

1. A 3 kΩ
2. B 6 kΩ
3. C 9 kΩ
4. D 12 kΩ

In the opposite figure, the equivalent resistance between points a and b is ..........

1. A 13 Ω
2. B 17 Ω
3. C 20 Ω
4. D 25 Ω

The equivalent resistance of the opposite circuit when an electric source is connected between points:
A and B equals ..........

1. A 20 Ω
2. B 17 Ω
3. C 9 Ω
4. D 5 Ω

The equivalent resistance of the opposite circuit when an electric source is connected between points:
C and B equals ..........

1. A 1.25 Ω
2. B 2.5 Ω
3. C 3.75 Ω
4. D 6.3 Ω

In the opposite figure:
the equivalent resistance when a battery of negligible internal resistance is connected between points X and Y is ..........

1. A 2 Ω
2. B 4 Ω
3. C 6 Ω
4. D 8 Ω

In the opposite figure:
if the battery is connected in place of the 7 Ω resistor, the equivalent resistance of the circuit becomes ..........

1. A 40 Ω
2. B 41 Ω
3. C 42 Ω
4. D 43 Ω

Three resistors (x), (y), (z) are connected together and with a battery and a rheostat (S) as in figure (1). Figure (2) shows graphically the relation between the potential difference (V) across each of the three resistors and the current (I) through each of them.
The equivalent resistance between points (a) and (b) shown in figure (1) equals ..........

1. A 1 Ω
2. B 3 Ω
3. C 4 Ω
4. D 11 Ω

A wire of resistance 48 Ω is bent into a closed ring, then a battery is connected across the two ends of one of its diameters as in the figure. The equivalent resistance between points A and B equals ..........

1. A 96 Ω
2. B 48 Ω
3. C 24 Ω
4. D 12 Ω

A straight wire of resistance R is bent into a circular ring and connected to an electric source in two different ways as shown in figures (1) and (2). The ratio between the equivalent resistances in the two figures $\left(\frac{R_1}{R_2}\right)$ equals ..........

1. A $\dfrac{3}{4}$
2. B $\dfrac{4}{3}$
3. C $\dfrac{2}{1}$
4. D $\dfrac{1}{2}$

A wire of uniform cross-section carries a current of 0.1 A when the potential difference across its ends is 1.2 V. If it is bent into a closed square abcd, the equivalent resistance of the wire when a battery is connected:
to points a and c equals ..........

1. A 2 Ω
2. B 3 Ω
3. C 4 Ω
4. D 6 Ω

A wire of uniform cross-section carries a current of 0.1 A when the potential difference across its ends is 1.2 V. If it is bent into a closed square abcd, the equivalent resistance of the wire when a battery is connected:
to points a and d equals ..........

1. A 6 Ω
2. B 4.5 Ω
3. C 2.25 Ω
4. D 1.5 Ω

In the opposite figure, if the equivalent resistance between points A and B is 9 Ω, the value of resistance R equals ..........

1. A 1 Ω
2. B 2 Ω
3. C 3 Ω
4. D 6 Ω

In the opposite figure, if the equivalent resistance between points A and B is 9 Ω, the value of resistance R equals ..........

1. A 4 Ω
2. B 6 Ω
3. C 12 Ω
4. D 18 Ω

In the opposite figure, if the equivalent resistance between points A and B is 9 Ω, the value of resistance R equals ..........

1. A 8 Ω
2. B 6 Ω
3. C 5 Ω
4. D 3 Ω

In the circuit shown in the figure, the value of R equals ..........

1. A 20 Ω
2. B 40 Ω
3. C 60 Ω
4. D 80 Ω

The opposite figure represents a closed electric circuit containing an unknown element X. If the voltmeter reading is 5 V, element X is ..........

1. A a resistance R
2. B a resistance 2R
3. C a resistance 3R
4. D a resistance 4R

A number (N) of resistors, each of 40 ohm, are all connected either in series or in parallel, then the two ends of the group are connected to an electric source of potential difference 120 volt, so a current of 15 ampere flows in the circuit. The number of resistors (N) equals ..........

1. A 3
2. B 4
3. C 5
4. D 6

An electric circuit in a house consists of an electric source of potential difference 110 V, a fuse whose wire withstands a maximum current of 5 A, and other parts connected in series with the source whose equivalent resistance is 2 Ω. What is the greatest number of identical lamps, each of resistance 620 Ω, that can be lit at the same time without damaging the fuse wire?

1. A 10
2. B 27
3. C 31
4. D 40

When a group of equal resistors is connected in series, its equivalent resistance is 100 Ω, and when connected in parallel, its equivalent resistance is 4 Ω. The value of one resistor equals ..........

1. A 20 Ω
2. B 25 Ω
3. C 100 Ω
4. D 104 Ω

Two resistors $R_1$ and $R_2$: when connected in parallel, their equivalent resistance is 6 Ω, and when connected in series, their equivalent resistance is 27 Ω. The value of one of the two resistors is ..........

1. A 8 Ω
2. B 12 Ω
3. C 15 Ω
4. D 18 Ω

A group of n identical electric resistors is connected once in series, giving an equivalent resistance $R_1$, and once again in parallel, giving an equivalent resistance $R_2$. The number of resistors (n) equals ..........

1. A $\dfrac{R_1}{R_2}$
2. B $\left(\dfrac{R_1}{R_2}\right)^2$
3. C $\sqrt{\dfrac{R_1}{R_2}}$
4. D $\sqrt{\dfrac{R_2}{R_1}}$

In the opposite figure, the difference between the two values of the equivalent resistance of the circuit when switch K is open and when it is closed equals ..........

1. A 1 Ω
2. B 2 Ω
3. C 4 Ω
4. D 6 Ω

In the opposite circuit, which resistors carry an electric current?

1. A $R_1$ only
2. B $R_1$, $R_2$
3. C $R_1$, $R_3$
4. D $R_1$, $R_2$, $R_3$

In the opposite figure, the equivalent resistance between points a and b is ..........

1. A 5 Ω
2. B 10 Ω
3. C 30 Ω
4. D 60 Ω

In the opposite figure, the equivalent resistance between points a and b is ..........

1. A 1 Ω
2. B 2 Ω
3. C 3 Ω
4. D 4 Ω

In the opposite figure, the equivalent resistance between points a and b is ..........

1. A 9 Ω
2. B 6 Ω
3. C 3 Ω
4. D 2 Ω

In the opposite figure, the equivalent resistance between points a and b is ..........

1. A 3 Ω
2. B 7 Ω
3. C 9 Ω
4. D 11 Ω

In the opposite figure, the equivalent resistance between points a and b is ..........

1. A 3 Ω
2. B 5 Ω
3. C 6 Ω
4. D 8 Ω

In the opposite figure, the equivalent resistance between points a and b is ..........

1. A 1 Ω
2. B 1.5 Ω
3. C 2 Ω
4. D 2.5 Ω

In the opposite figure, the equivalent resistance between points a and b is ..........

1. A 1 Ω
2. B 3 Ω
3. C 6 Ω
4. D 12 Ω

In the opposite figure, the equivalent resistance between points a and b is ..........

1. A 45 Ω
2. B 72 Ω
3. C 90 Ω
4. D 110 Ω

In the opposite figure, the equivalent resistance between points a and b is ..........

1. A 0
2. B 1 Ω
3. C 2 Ω
4. D 5 Ω

In the opposite figure, the equivalent resistance between points a and b is ..........

1. A 4 Ω
2. B 7 Ω
3. C 14 Ω
4. D 15 Ω

In the opposite figure, the equivalent resistance between points a and b is ..........

1. A R
2. B 2R
3. C 3R
4. D 6R

In the opposite figure, the equivalent resistance between points a and b is ..........

1. A 18 Ω
2. B 12 Ω
3. C 9 Ω
4. D 6 Ω

In the opposite circuit, the equivalent resistance when switch K is open and when it is closed, respectively, is ..........

1. A K open: 9 Ω, K closed: 10 Ω
2. B K open: 9 Ω, K closed: 9 Ω
3. C K open: 6 Ω, K closed: 3 Ω
4. D K open: 6 Ω, K closed: 6 Ω

In the opposite circuit, the equivalent resistance when switch K is open and when it is closed, respectively, is ..........

1. A K open: 0, K closed: 2 Ω
2. B K open: 2 Ω, K closed: 0
3. C K open: 8 Ω, K closed: 0
4. D K open: 4 Ω, K closed: 0

In the opposite circuit, the equivalent resistance when switch K is open and when it is closed, respectively, is ..........

1. A K open: 8 Ω, K closed: 2 Ω
2. B K open: 9 Ω, K closed: 4 Ω
3. C K open: 8 Ω, K closed: 4 Ω
4. D K open: 36 Ω, K closed: 6 Ω

In the opposite circuit, the equivalent resistance when switch K is open and when it is closed, respectively, is ..........

1. A K open: 7.5 Ω, K closed: 6 Ω
2. B K open: 3 Ω, K closed: 6 Ω
3. C K open: 15 Ω, K closed: 7.5 Ω
4. D K open: 7.5 Ω, K closed: 3.5 Ω

In the opposite circuit, the equivalent resistance when switch K is open and when it is closed, respectively, is ..........

1. A K open: 20 Ω, K closed: 10 Ω
2. B K open: 20 Ω, K closed: 15 Ω
3. C K open: 15 Ω, K closed: 20 Ω
4. D K open: 10 Ω, K closed: 20 Ω

In the opposite circuit, the equivalent resistance when switch K is open and when it is closed, respectively, is ..........

1. A K open: 10 Ω, K closed: 22.5 Ω
2. B K open: 25 Ω, K closed: 22.5 Ω
3. C K open: 25 Ω, K closed: 7.5 Ω
4. D K open: 30 Ω, K closed: 15 Ω

In the opposite circuit, when the switch is closed, the equivalent resistance of the circuit decreases to half its value. The value of resistance R equals ..........

1. A 3 Ω
2. B 5 Ω
3. C 7 Ω
4. D 11 Ω

Five identical resistors are connected together as in the opposite figure, and their equivalent resistance is $R_o$. If the five resistors are reconnected in several ways, which of the ways of connection in the following figures makes the equivalent resistance of the group $\frac{1}{2} R_o$?

1. A A
2. B B
3. C C
4. D D

Four identical resistors are connected in different ways as in the following figures. In which of these figures is the equivalent resistance between points a and b the greatest?

1. A A
2. B B
3. C C
4. D D

The equivalent resistance of the group of resistors shown in the opposite figure when an electric source is connected:
to points A and B equals ..........

1. A 2 Ω
2. B 4 Ω
3. C 6 Ω
4. D 8 Ω

The equivalent resistance of the group of resistors shown in the opposite figure when an electric source is connected:
to points B and C equals ..........

1. A 3.75 Ω
2. B 6 Ω
3. C 7.5 Ω
4. D 10 Ω

In the opposite figure, if each resistance = R, the equivalent resistance of the group = ..........

1. A 6R
2. B 3R
3. C $\dfrac{R}{2}$
4. D $\dfrac{R}{6}$

In the two opposite electric circuits, the currents $I_1$ and $I_2$ are equal. The ratio between the emfs of the two batteries $\left(\frac{(V_B)_1}{(V_B)_2}\right)$ equals ..........

1. A $\dfrac{R_y}{R_x}$
2. B $\dfrac{R_x}{R_y}$
3. C $\dfrac{R_x + R_y}{R_y}$
4. D $\dfrac{R_x + R_y}{R_x}$

The opposite figure represents part of an electric circuit. If the ammeter reading is zero, the value of resistance R equals ..........

1. A 8 Ω
2. B 9 Ω
3. C 12 Ω
4. D 24 Ω

In the opposite electric circuit, what is the value of resistance $R_{cd}$ if the potential difference across the 4 Ω resistor is zero?

1. A 0.5 Ω
2. B 1 Ω
3. C 2 Ω
4. D 4 Ω

In the opposite figure, the ratio between the two values of the equivalent resistance when switch K is open and when it is closed, respectively, equals ..........

1. A $\dfrac{1}{3}$
2. B $\dfrac{1}{2}$
3. C $\dfrac{4}{3}$
4. D $\dfrac{5}{2}$

The following figures represent four electric circuits.
The circuits in which no electric current flows in the 5 Ω resistor are ..........

1. A (1), (2) only
2. B (3), (4) only
3. C (1), (2), (3) only
4. D (2), (3), (4) only

A metal wire of uniform cross-section and electric resistance (R) is divided into four identical parts, and these parts are connected together as in the opposite figure. The equivalent resistance of the group between points (a) and (b) equals ..........

1. A $\dfrac{R}{12}$
2. B $\dfrac{R}{6}$
3. C $\dfrac{R}{4}$
4. D $\dfrac{R}{3}$

Two uninsulated conductors x and y of uniform cross-section have lengths ℓ and 2ℓ, cross-sectional areas A and 2A, and electric conductivities of their materials 8σ and σ, respectively. They are placed in full contact as in the opposite figure. If the electric resistance of conductor x is 5 Ω, their equivalent resistance when an electric source is connected between points a and b equals ..........

1. A 7.5 Ω
2. B 14 Ω
3. C 20 Ω
4. D 24 Ω

Two conductors of uniform cross-section, made of the same material and having the same cross-sectional area, are connected together by two sliders (1) and (2) and included in an electric circuit as shown in the opposite figure; their equivalent resistance is R. When slider (1) is moved to position (b), their equivalent resistance becomes ..........

1. A $\dfrac{R}{2}$
2. B $\dfrac{2}{3}$ R
3. C $\dfrac{3}{2}$ R
4. D 2R

In figure (1), a wire of uniform cross-section has length (ℓ) and resistance (R). It is cut into two halves, one of the halves is stretched, then the two are connected together again so that the length of the whole wire becomes (3ℓ) as in figure (2).
The total resistance of the wire in figure (2) equals ..........

1. A 12.5 R
2. B 13 R
3. C 25 R
4. D 25.5 R

In which of the following electric circuits is the current in one of the two resistors different from that in the other resistor?

1. A A
2. B B
3. C C
4. D D

In the electric circuit shown, if the reading of ammeter $A_1$ is 1.2 A, the reading of ammeter $A_2$ equals ..........

1. A 0.2 A
2. B 0.4 A
3. C 0.6 A
4. D 0.8 A

Four resistors are connected in parallel to a battery of emf 9.2 V, and the currents through them are 4 mA, 14 mA, 45 mA and 150 mA as shown in the opposite figure. Then:
the total resistance of the circuit equals ..........

1. A 9.71 Ω
2. B 13.35 Ω
3. C 29.53 Ω
4. D 43.19 Ω

Four resistors are connected in parallel to a battery of emf 9.2 V, and the currents through them are 4 mA, 14 mA, 45 mA and 150 mA as shown in the opposite figure. Then:
the total current through the battery if the largest resistor is replaced by another of double its value equals ..........

1. A 105.5 mA
2. B 211 mA
3. C 422 mA
4. D 633 mA

In the figure shown:
the reading of ammeter $A_1$ equals ..........

1. A 2 A
2. B 4 A
3. C 6 A
4. D 8 A

In the figure shown:
the reading of ammeter $A_2$ equals ..........

1. A 1 A
2. B 2 A
3. C 3 A
4. D 4 A

In the circuit shown:
the equivalent resistance of the circuit equals ..........

1. A 5 Ω
2. B 9 Ω
3. C 11 Ω
4. D 13 Ω

In the circuit shown:
the total current in the circuit equals ..........

1. A 0.5 A
2. B 2 A
3. C 3.5 A
4. D 4 A

In the circuit shown:
the electric current through the 6 Ω resistor equals ..........

1. A 0.13 A
2. B 0.91 A
3. C 0.33 A
4. D 0.45 A

In which of the following figures is the potential difference across the 4 Ω resistor equal to 4 V?

1. A A
2. B B
3. C C
4. D D

In the opposite figure, the ratio $\left(\frac{I_1}{I}\right)$ is ..........

1. A $\dfrac{1}{2}$
2. B $\dfrac{1}{3}$
3. C $\dfrac{1}{4}$
4. D $\dfrac{1}{6}$

In the opposite figure, the currents $I_1$ and $I_2$ are ..........

1. A $I_1$ = 1 A, $I_2$ = 5 A
2. B $I_1$ = 2 A, $I_2$ = 4 A
3. C $I_1$ = 4 A, $I_2$ = 2 A
4. D $I_1$ = 5 A, $I_2$ = 1 A

In the opposite figure, the currents $I_1$ and $I_2$ are ..........

1. A $I_1$ = 3 A, $I_2$ = 6 A
2. B $I_1$ = 3 A, $I_2$ = 9 A
3. C $I_1$ = 6 A, $I_2$ = 6 A
4. D $I_1$ = 6 A, $I_2$ = 9 A

In the opposite figure, the currents $I_1$ and $I_2$ are ..........

1. A $I_1$ = 4 A, $I_2$ = 6 A
2. B $I_1$ = 4 A, $I_2$ = 3 A
3. C $I_1$ = 1 A, $I_2$ = 4 A
4. D $I_1$ = 1 A, $I_2$ = 5 A

In the opposite figure, the currents $I_1$ and $I_2$ are ..........

1. A $I_1$ = $\dfrac{1}{2}$ A, $I_2$ = $\dfrac{3}{2}$ A
2. B $I_1$ = $\dfrac{1}{2}$ A, $I_2$ = $\dfrac{5}{3}$ A
3. C $I_1$ = $\dfrac{2}{3}$ A, $I_2$ = $\dfrac{5}{3}$ A
4. D $I_1$ = $\dfrac{2}{3}$ A, $I_2$ = $\dfrac{1}{2}$ A

In the opposite figure, the currents $I_1$ and $I_2$ are ..........

1. A $I_1$ = 6 A, $I_2$ = 5 A
2. B $I_1$ = 6 A, $I_2$ = 9 A
3. C $I_1$ = 12 A, $I_2$ = 5 A
4. D $I_1$ = 12 A, $I_2$ = 9 A

In the opposite figure, the currents $I_1$ and $I_2$ are ..........

1. A $I_1$ = 0.5 A, $I_2$ = 2 A
2. B $I_1$ = 1 A, $I_2$ = 2 A
3. C $I_1$ = 0.5 A, $I_2$ = 4 A
4. D $I_1$ = 1 A, $I_2$ = 4 A

In the opposite electric circuit, the ratio $\left(\frac{I_2}{I_3}\right)$ is ..........

1. A $\dfrac{1}{4}$
2. B $\dfrac{1}{3}$
3. C $\dfrac{1}{2}$
4. D $\dfrac{3}{4}$

The opposite figure represents part of an electric circuit. The ratio between the two currents $\left(\frac{I_1}{I_2}\right)$ equals ..........

1. A $\dfrac{1}{1}$
2. B $\dfrac{2}{1}$
3. C $\dfrac{1}{2}$
4. D $\dfrac{1}{4}$

In the opposite figure, if the ammeter reading is 1 A, the current through the 12 Ω resistor equals ..........

1. A 0.5 A
2. B 1 A
3. C 1.5 A
4. D 2 A

The opposite figure shows a simple electric circuit. When switch K is closed, the ammeter reading is 5 A. When a 2 Ω resistor is connected in series with resistor R in the circuit, the ammeter reading decreases to 4 A. The value of resistance R is ..........

1. A 4 Ω
2. B 8 Ω
3. C 12 Ω
4. D 16 Ω

In the opposite circuit, if the reading of ammeter $A_1$ is zero, then when switch K is opened, the reading of ammeter $A_2$ ..........

1. A increases
2. B decreases
3. C does not change
4. D becomes zero

In the opposite circuit:
what is the ammeter reading when switch K is open?

1. A 0.21 A
2. B 0.3 A
3. C 0.43 A
4. D 1.6 A

In the opposite circuit:
what is the ammeter reading when switch K is closed?

1. A 5.4 A
2. B 1.52 A
3. C 0.34 A
4. D 0.22 A

Which of the following graphs represents the relation between the ammeter reading and the value of the rheostat S?

1. A A
2. B B
3. C C
4. D D

If the ammeter reading in the opposite circuit is 2 A, then:
the current in the circuit equals ..........

1. A 6 A
2. B 9 A
3. C 5 A
4. D 3 A

If the ammeter reading in the opposite circuit is 2 A, then:
the value of resistance R equals ..........

1. A 4 Ω
2. B 2 Ω
3. C 1 Ω
4. D 0.5 Ω

In the electric circuit shown, the reading of ammeter (A) equals ..........

1. A 1 A
2. B 2 A
3. C 3 A
4. D 4 A

Three resistors of 6 Ω, 3 Ω and 1 Ω are connected to an electric source, and the currents through them are 0.1 A, 0.2 A and 0.3 A, respectively. The equivalent resistance of the electric circuit equals ..........

1. A 1 Ω
2. B 2 Ω
3. C 3 Ω
4. D 4 Ω

In the opposite circuit, the ratio $\left(\frac{R_1}{R_2}\right)$ is ..........

1. A $\dfrac{3}{2}$
2. B $\dfrac{3}{1}$
3. C $\dfrac{4}{1}$
4. D $\dfrac{4}{3}$

Three conductors (x), (y), (z) of the same metal and the same cross-sectional area but of different lengths are connected together in parallel, then to a battery of emf 6 V and negligible internal resistance as in the opposite circuit. If the current in conductor (x) is 3 A, the current in the circuit when the conductors are connected together in series to the same battery equals ..........

1. A $\dfrac{2}{11}$ A
2. B $\dfrac{3}{11}$ A
3. C $\dfrac{6}{11}$ A
4. D $\dfrac{9}{11}$ A

In the opposite electric circuit, if $I_1 = I_2$, then ..........

1. A $(\rho_e)_3 = (\rho_e)_1 + (\rho_e)_2$
2. B $(\rho_e)_3 = (\rho_e)_1 + 2(\rho_e)_2$
3. C $(\rho_e)_3 = 2(\rho_e)_1 + \dfrac{(\rho_e)_2}{2}$
4. D $(\rho_e)_3 = \sqrt{(\rho_e)_1 + (\rho_e)_2}$

A metal rod (xyz) of uniform cross-section, length ℓ and electric resistance R is connected in an electric circuit as in the opposite figure. At which of the positions shown on the rod should the slider be placed so that the ammeter gives the greatest possible reading?

1. A At position (x)
2. B At position (y)
3. C At position (z)
4. D The ammeter readings are equal at the three positions

In the circuit shown, the ratio between the readings of the two ammeters $\left(\frac{A_1}{A_2}\right)$ is ..........

1. A $\dfrac{1}{2}$
2. B $\dfrac{2}{3}$
3. C $\dfrac{1}{1}$
4. D $\dfrac{3}{2}$

The ratio between the readings of the two ammeters $\left(\frac{A_1}{A_2}\right)$ in the opposite electric circuit equals ..........

1. A $\dfrac{1}{1}$
2. B $\dfrac{2}{1}$
3. C $\dfrac{3}{1}$
4. D $\dfrac{3}{2}$

In the opposite circuit, when the value of the rheostat S is increased, the ammeter reading ..........

1. A increases
2. B becomes zero
3. C does not change
4. D decreases but does not become zero

The opposite figure shows three resistors x, y, z connected together in parallel. The ratio of the currents through them $I_x : I_y : I_z$ is ..........

1. A $6 : 3 : 2$
2. B $3 : 2 : 1$
3. C $2 : 3 : 1$
4. D $2 : 3 : 6$

Which of the following graphs represents the relation between the reading of ammeter $A_1$ and the reading of ammeter $A_2$ when the value of resistance R in the opposite electric circuit is changed? (Note: $I_1$ and $I_2$ are drawn to the same scale)

1. A A
2. B B
3. C C
4. D D

The opposite figure shows three resistors x, y, z connected together in series. The ratio of the potential differences across them $V_x : V_y : V_z$ equals ..........

1. A $3 : 2 : 1$
2. B $2 : 3 : 1$
3. C $1 : 1 : 1$
4. D $1 : 2 : 3$

In the opposite electric circuit, three identical resistors are connected to an electric source. When switch K is closed ..........

1. A the current in R decreases and the current in Q increases
2. B the current in R decreases and the current in Q decreases
3. C the current in R increases and the current in Q decreases
4. D the current in R increases and the current in Q increases

In the opposite electric circuit, if the electric resistors are identical, what happens to the ammeter reading when only switch $K_1$ is closed, and when only switch $K_2$ is closed?

1. A Closing $K_1$ only: decreases, closing $K_2$ only: increases
2. B Closing $K_1$ only: decreases, closing $K_2$ only: does not change
3. C Closing $K_1$ only: does not change, closing $K_2$ only: increases
4. D Closing $K_1$ only: does not change, closing $K_2$ only: does not change

A current of 3 mA flows in a wire ab. If another wire of the same material, the same length and three times the diameter of wire ab is connected in parallel with it, the total current that must flow so that the potential difference across wire ab stays constant is ..........

1. A 0.02 A
2. B 0.1 A
3. C 0.03 A
4. D 0.5 A

Two wires A and B have the same length and are made of the same material. The cross-sectional area of wire A is double that of wire B. They are connected together in parallel in an electric circuit, and when the circuit is closed the current in the circuit is 3 A. The currents through them $I_A$ and $I_B$, respectively, are ..........

1. A $I_A$ = 2 A, $I_B$ = 1 A
2. B $I_A$ = 2 A, $I_B$ = 3 A
3. C $I_A$ = 3 A, $I_B$ = 3 A
4. D $I_A$ = 2 A, $I_B$ = 2 A

An electric circuit consists of a DC source of negligible internal resistance and a thin metal wire, and a current of 8 mA flows in it. If another wire of the same length and the same metal is connected in parallel with this wire in the same circuit, a current of 10 mA flows. The ratio between the radii of the two wires $\left(\frac{r_1}{r_2}\right)$ equals ..........

1. A $\dfrac{1}{2}$
2. B $\dfrac{3}{2}$
3. C $\dfrac{2}{1}$
4. D $\dfrac{5}{3}$

In the circuit shown in the figure, the ammeter reading equals ..........

1. A I
2. B $\dfrac{I}{2}$
3. C $\dfrac{I}{3}$
4. D $\dfrac{I}{6}$

In the opposite figure, if the current through resistor $R_1$ is 2 A, the equivalent resistance of the circuit equals ..........

1. A 3 Ω
2. B 4 Ω
3. C 6 Ω
4. D 12 Ω

The ammeter reading in the opposite electric circuit equals .......... (Note: the resistance of the ammeter is negligible)

1. A 1 A
2. B 1.2 A
3. C 2 A
4. D 2.4 A

In the electric circuit shown, the current through the battery has its smallest value when switch .......... is closed.

1. A 1
2. B 2
3. C 3
4. D 4

In the opposite electric circuit, the ratio between the values of the two resistors $\left(\frac{R_1}{R_2}\right)$ equals ..........

1. A $\dfrac{1}{2}$
2. B $\dfrac{1}{4}$
3. C $\dfrac{1}{8}$
4. D $\dfrac{1}{16}$

In the opposite figure, the ratio between the readings of the two voltmeters $\left(\frac{V_1}{V_2}\right)$ equals ..........

1. A $\dfrac{1}{2}$
2. B $\dfrac{1}{3}$
3. C $\dfrac{2}{1}$
4. D $\dfrac{3}{1}$

In the opposite electric circuit, what happens to the readings of the two ammeters $A_1$ and $A_2$, respectively, when:
only switch $K_1$ is closed?

1. A does not change, increases
2. B decreases, does not change
3. C does not change, does not change
4. D increases, decreases

In the opposite electric circuit, what happens to the readings of the two ammeters $A_1$ and $A_2$, respectively, when:
only switch $K_2$ is closed?

1. A increases, becomes zero
2. B decreases, becomes zero
3. C becomes zero, decreases
4. D becomes zero, increases

In the opposite electric circuit, what happens to the readings of the two ammeters $A_1$ and $A_2$, respectively, when:
only switch $K_3$ is closed?

1. A increases, decreases
2. B increases, does not change
3. C does not change, increases
4. D decreases, increases

Each of the following electric circuits consists of a battery of negligible internal resistance, a number of identical resistors and an ammeter.
If the ammeter reading is the same in all of them, the correct order of the emfs of these batteries is ..........

1. A $(V_B)_1 > (V_B)_2 > (V_B)_3$
2. B $(V_B)_3 > (V_B)_2 > (V_B)_1$
3. C $(V_B)_2 > (V_B)_1 > (V_B)_3$
4. D $(V_B)_2 > (V_B)_3 > (V_B)_1$

In the electric circuit shown in the figure, the current through the 20 Ω resistor does not change whether the two switches $K_1$ and $K_2$ are both closed or both open. Resistance R equals ..........

1. A 50 Ω
2. B 100 Ω
3. C 150 Ω
4. D 200 Ω

In the opposite electric circuit, wire ae has a uniform cross-section and a resistance of 24 Ω, and the ammeter reading is $(I_1)$. When the slider is moved from position b to position d, the ammeter reading becomes $(I_2)$. The ratio $\left(\frac{I_1}{I_2}\right)$ equals ..........

1. A $\dfrac{1}{2}$
2. B $\dfrac{2}{1}$
3. C $\dfrac{3}{5}$
4. D $\dfrac{5}{3}$

Two uninsulated metal conductors (ab) and (bc) have the same cross-sectional area, lengths ℓ and 2ℓ, and resistivities of their materials $(\rho_e)$ and $(2\rho_e)$, respectively. The two conductors are connected together in an electric circuit as in the following figure, and the following table shows how the ammeter reading changes with the position of the slider in the circuit:
Slider at a: ammeter reading I
Slider at b: ammeter reading $\frac{1}{2}$ I
Slider at c: ammeter reading ?
The ammeter reading when the slider is at position (c) becomes ..........

1. A $\dfrac{1}{3}$ I
2. B $\dfrac{1}{4}$ I
3. C $\dfrac{1}{6}$ I
4. D $\dfrac{1}{8}$ I

Several electric resistors are connected together and carry currents as shown in the opposite figure. The correct order of the resistors $R_1$, $R_2$, $R_3$ by value is ..........

1. A $R_3 < R_2 < R_1$
2. B $R_3 > R_2 > R_1$
3. C $R_3 = R_2 > R_1$
4. D $R_3 = R_2 < R_1$

In the opposite circuit, the readings of the two voltmeters $V_1$ and $V_2$ are ..........

1. A $V_1$ = 10 V, $V_2$ = 10 V
2. B $V_1$ = 10 V, $V_2$ = 20 V
3. C $V_1$ = 20 V, $V_2$ = 10 V
4. D $V_1$ = 20 V, $V_2$ = 20 V

In the opposite circuit, the readings of the two voltmeters $V_1$ and $V_2$ are ..........

1. A $V_1$ = 16 V, $V_2$ = 36 V
2. B $V_1$ = 16 V, $V_2$ = 40 V
3. C $V_1$ = 36 V, $V_2$ = 36 V
4. D $V_1$ = 36 V, $V_2$ = 40 V

In the opposite circuit, the readings of the two voltmeters $V_1$ and $V_2$ are ..........

1. A $V_1$ = 10 V, $V_2$ = 10 V
2. B $V_1$ = 10 V, $V_2$ = 40 V
3. C $V_1$ = 40 V, $V_2$ = 10 V
4. D $V_1$ = 40 V, $V_2$ = 40 V

In the opposite circuit, the readings of the two voltmeters $V_1$ and $V_2$ are ..........

1. A $V_1$ = 1 V, $V_2$ = 1.5 V
2. B $V_1$ = 1 V, $V_2$ = 2.5 V
3. C $V_1$ = 2 V, $V_2$ = 1.5 V
4. D $V_1$ = 2 V, $V_2$ = 2.5 V

In the opposite circuit, the readings of the two voltmeters $V_1$ and $V_2$ are ..........

1. A $V_1$ = 1.5 V, $V_2$ = 3 V
2. B $V_1$ = 1.5 V, $V_2$ = 1.5 V
3. C $V_1$ = 3 V, $V_2$ = 6 V
4. D $V_1$ = 3 V, $V_2$ = 3 V

In the opposite circuit, the readings of the two voltmeters $V_1$ and $V_2$ are ..........

1. A $V_1$ = 12 V, $V_2$ = 12 V
2. B $V_1$ = 4 V, $V_2$ = 12 V
3. C $V_1$ = 16 V, $V_2$ = 16 V
4. D $V_1$ = 8 V, $V_2$ = 16 V

In an experiment to verify Ohm's law practically using the opposite electric circuit, when the resistance taken from the rheostat was 20 Ω, the ammeter reading was 150 mA. Which of the following graphs correctly represents the relation between the ammeter reading (I) and the voltmeter reading (V) in this circuit?

1. A A
2. B B
3. C C
4. D D

The opposite figure represents part of an electric circuit consisting of a battery of emf 2 V and negligible internal resistance, and a voltmeter. Which of the following figures completes this circuit at points X, Y, Z so that the voltmeter reads 1.5 V? (Consider the voltmeter resistance infinite)

1. A A
2. B B
3. C C
4. D D

In the electric circuit shown in the opposite figure, the ratio between the readings of the two voltmeters $\left(\frac{V_1}{V_2}\right)$ is ..........

1. A $\dfrac{1}{1}$
2. B $\dfrac{1}{2}$
3. C $\dfrac{1}{3}$
4. D $\dfrac{1}{6}$

In the electric circuit shown in the figure, if the voltmeter reading is 4 V, the electric current through the 6 Ω resistor equals ..........

1. A 0.8 A
2. B 1 A
3. C 1.2 A
4. D 2 A

If the resistance of the voltmeter in the figure is 100 kΩ, what is its reading?

1. A 0
2. B 2 V
3. C 3 V
4. D 4 V

The opposite figure represents part of an electric circuit. Then:
the voltmeter reading (V) equals ..........

1. A 8 V
2. B 4 V
3. C 2.5 V
4. D 1.3 V

The opposite figure represents part of an electric circuit. Then:
the value of resistance $R_2$ equals ..........

1. A 3 Ω
2. B 5 Ω
3. C 9 Ω
4. D 16 Ω

From the opposite circuit, the potential difference across the source (V) is ..........

1. A 25 V
2. B 50 V
3. C 75 V
4. D 100 V

In the opposite figure, there are two fixed resistors x and z and a variable resistor y whose range is from zero to 3000 Ω. The range of the potential difference between points a and b is from ..........

1. A 0 to 6 V
2. B 3 V to 6 V
3. C 4.5 V to 6 V
4. D 4.5 V to 9 V

The opposite figure represents part of an electric circuit. If the voltmeter reads 1 V, the potential difference between points X and Y equals ..........

1. A 1 V
2. B 2 V
3. C 3 V
4. D 4 V

In the figure in front of you, the voltmeter reading when:
switch $K_2$ is closed and switch $K_1$ is open equals ..........

1. A 20 V
2. B 30 V
3. C 60 V
4. D 40 V

In the figure in front of you, the voltmeter reading when:
switch $K_2$ is closed and switch $K_1$ is closed equals ..........

1. A 30 V
2. B 40 V
3. C 90 V
4. D 60 V

In the figure in front of you, the voltmeter reading when:
switch $K_2$ is open and switch $K_1$ is closed equals ..........

1. A 0
2. B 20 V
3. C 40 V
4. D 60 V

The opposite figure represents part of an electric circuit. If the potential difference $V_{ab}$ is 200 V, then:
the equivalent resistance of this part equals ..........

1. A 100 Ω
2. B 80 Ω
3. C 75 Ω
4. D 54 Ω

The opposite figure represents part of an electric circuit. If the potential difference $V_{ab}$ is 200 V, then:
the current through resistor $R_1$ equals ..........

1. A 5 A
2. B 3.5 A
3. C 2 A
4. D 1.6 A

The opposite figure represents part of an electric circuit. If the potential difference $V_{ab}$ is 200 V, then:
the current in resistor $R_5$ equals ..........

1. A 0.1 A
2. B 0.4 A
3. C 1.4 A
4. D 1.6 A

The opposite figure represents part of an electric circuit. If the potential difference $V_{ab}$ is 200 V, then:
the potential difference between points d and e equals ..........

1. A 16 V
2. B 12 V
3. C 10 V
4. D 8 V

Three resistors of 20 Ω, 40 Ω and 60 Ω are connected to a source of electric current. If the potential differences across them are 50 V, 20 V and 30 V, respectively, the equivalent resistance of the circuit equals ..........

1. A 16.67 Ω
2. B 12.23 Ω
3. C 10.53 Ω
4. D 9.75 Ω

A voltmeter of resistance 500 Ω is connected in parallel with an unknown resistance, then an ammeter of negligible resistance is connected in series with them. When the two ends of the group are connected to an electric cell, the ammeter reading is 0.01 A and the voltmeter reading is 3 V. The value of the unknown resistance is ..........

1. A 900 Ω
2. B 800 Ω
3. C 750 Ω
4. D 620 Ω

In the opposite electric circuit, what happens to the readings of the ammeter and the voltmeter, respectively, when switch K is closed?

1. A Ammeter reading increases, voltmeter reading increases
2. B Ammeter reading decreases, voltmeter reading decreases
3. C Ammeter reading decreases, voltmeter reading increases
4. D Ammeter reading increases, voltmeter reading decreases

In the opposite electric circuit, what happens to the readings of the ammeter and the voltmeter, respectively, when switch K is closed?

1. A Ammeter reading increases, voltmeter reading increases
2. B Ammeter reading decreases, voltmeter reading does not change
3. C Ammeter reading increases, voltmeter reading decreases
4. D Ammeter reading does not change, voltmeter reading does not change

In the opposite electric circuit, what happens to the readings of the ammeter and the voltmeter, respectively, when switch K is closed?

1. A Ammeter reading increases, voltmeter reading increases
2. B Ammeter reading decreases, voltmeter reading does not change
3. C Ammeter reading does not change, voltmeter reading decreases
4. D Ammeter reading does not change, voltmeter reading does not change

In the opposite electric circuit, what happens to the readings of the ammeter and the voltmeter, respectively, when switch K is closed?

1. A Ammeter reading increases, voltmeter reading increases
2. B Ammeter reading decreases, voltmeter reading does not change
3. C Ammeter reading does not change, voltmeter reading decreases
4. D Ammeter reading does not change, voltmeter reading does not change

In the opposite electric circuit, what happens to the readings of the ammeter (A) and the two voltmeters $(V_1)$ and $(V_2)$ when switch (K) is opened?

1. A Ammeter decreases, $V_1$ increases, $V_2$ increases
2. B Ammeter decreases, $V_1$ increases, $V_2$ decreases
3. C Ammeter increases, $V_1$ increases, $V_2$ increases
4. D Ammeter increases, $V_1$ decreases, $V_2$ decreases

In the opposite figure, the readings of the ammeter and the voltmeter, respectively, when:
the two switches $S_2$ and $S_1$ are both closed are ..........

1. A Ammeter 0.67 A, voltmeter 0.2 V
2. B Ammeter 0, voltmeter 0.3 V
3. C Ammeter 0.67 A, voltmeter 0
4. D Ammeter 0.5 A, voltmeter 0.3 V

In the opposite figure, the readings of the ammeter and the voltmeter, respectively, when:
switch $S_1$ is closed and switch $S_2$ is open are ..........

1. A Ammeter 3.2 A, voltmeter 1.2 V
2. B Ammeter 0.25 A, voltmeter 1.25 V
3. C Ammeter 1.25 A, voltmeter 3.2 V
4. D Ammeter 0.25 A, voltmeter 2.05 V

In the opposite electric circuit, what happens to the readings of the ammeter and the voltmeter, respectively, when the value of the rheostat S is increased?

1. A Ammeter reading decreases, voltmeter reading decreases
2. B Ammeter reading decreases, voltmeter reading does not change
3. C Ammeter reading does not change, voltmeter reading increases
4. D Ammeter reading does not change, voltmeter reading does not change

In the opposite electric circuit, what happens to the readings of the ammeter and the voltmeter, respectively, when the value of the rheostat S is increased?

1. A Ammeter reading decreases, voltmeter reading decreases
2. B Ammeter reading decreases, voltmeter reading increases
3. C Ammeter reading increases, voltmeter reading decreases
4. D Ammeter reading increases, voltmeter reading increases

In the opposite electric circuit, what happens to the readings of the ammeter and the voltmeter, respectively, when the value of the rheostat S is increased?

1. A Ammeter reading decreases, voltmeter reading decreases
2. B Ammeter reading decreases, voltmeter reading increases
3. C Ammeter reading increases, voltmeter reading decreases
4. D Ammeter reading increases, voltmeter reading increases

In the opposite electric circuit, what happens to the readings of the ammeter and the voltmeter, respectively, when the value of the rheostat S is increased?

1. A Ammeter reading decreases, voltmeter reading decreases
2. B Ammeter reading decreases, voltmeter reading increases
3. C Ammeter reading increases, voltmeter reading decreases
4. D Ammeter reading increases, voltmeter reading increases

In the opposite figure:
when the switch is closed in direction (1), a current of 2 A flows in the ammeter, so the value of resistance R is ..........

1. A 30 Ω
2. B 5 Ω
3. C 7.5 Ω
4. D 2.5 Ω

In the opposite figure:
when the switch is closed in direction (2), the current in the ammeter is ..........

1. A 1 A
2. B 2 A
3. C 3 A
4. D 4 A

In the opposite electric circuit, between which two points does moving a free electron require the greatest work done?

1. A x and y
2. B y and z
3. C z and m
4. D z and n

In the electric circuit shown, the potential difference between points b and d equals ..........

1. A 2 V
2. B 4 V
3. C 6 V
4. D 8 V

In the opposite figure, the potential difference between x and y equals ..........

1. A 0
2. B 3 IR
3. C 6 IR
4. D IR

The figure shows part of an electric circuit. Which of the following relations is correct for the potential differences between the points shown in the figure?

1. A $V_{k\ell} > V_{xy}$
2. B $V_{yz} > V_{xk}$
3. C $V_{xy} = V_{kz}$
4. D $V_{xz} = 2 V_{\ell z}$

In the opposite electric circuit, the values of $R_1$ and $R_2$, respectively, are ..........

1. A $R_1$ = 2.5 Ω, $R_2$ = 5 Ω
2. B $R_1$ = 2.5 Ω, $R_2$ = 10 Ω
3. C $R_1$ = 5 Ω, $R_2$ = 2.5 Ω
4. D $R_1$ = 5 Ω, $R_2$ = 10 Ω

In the opposite figure, if the voltmeter reading is 4 V:
what is its reading when it is connected between points c and b?

1. A 10 V
2. B 8 V
3. C 6 V
4. D 2 V

In the opposite figure, if the voltmeter reading is 4 V:
what is its reading when it is connected between points c and a?

1. A 14 V
2. B 15 V
3. C 16 V
4. D 17 V

The opposite figure shows part of an electric circuit. The correct mathematical relation between the potential differences $V_1$, $V_2$, $V_3$ is ..........

1. A $V_1 = V_2 > V_3$
2. B $V_1 = V_2 < V_3$
3. C $V_1 > V_3 > V_2$
4. D $V_1 > V_2 > V_3$

The opposite figure represents part of an electric circuit. Which of the following mathematical relations is the correct relation between the electric potentials at points a, b, c?

1. A $V_a > V_b > V_c$
2. B $V_a < V_b < V_c$
3. C $V_a > V_b = V_c$
4. D $V_a < V_b = V_c$

The opposite figure shows a closed electric circuit. If $V_1 = V_2$, the value of resistance R equals ..........

1. A 3 Ω
2. B 9 Ω
3. C 12 Ω
4. D 15 Ω

In the circuit shown, if $\left(\frac{V_1}{V_2} = \frac{3}{4}\right)$, the value of resistance R equals ..........

1. A 6 Ω
2. B 12 Ω
3. C 18 Ω
4. D 24 Ω

In the opposite electric circuit, the readings of the two voltmeters $V_1$ and $V_2$ are equal. The relation between $R_1$ and $R_2$ is ..........

1. A $R_1 = R_2$
2. B $R_1 > R_2$
3. C $R_1 < R_2$
4. D The answer cannot be determined

In the two opposite circuits, if the readings of voltmeters $V_1$ and $V_3$ are equal and the readings of voltmeters $V_2$ and $V_4$ are equal, then ..........

1. A R = 6 Ω, $I_2$ = $\dfrac{2}{3}$ A
2. B R = 6 Ω, $I_2$ = $\dfrac{1}{3}$ A
3. C R = 15 Ω, $I_2$ = $\dfrac{2}{3}$ A
4. D R = 15 Ω, $I_2$ = $\dfrac{1}{3}$ A

Three solid conductors ab, bc, cd are made of the same metal, have the same length (ℓ) and uniform cross-sections, and their cross-sectional areas are 3A, 2A and A, respectively, as in the opposite figure. The ratio between:
the potential differences $\left(\frac{V_{cd}}{V_{bc}}\right)$ equals ..........

1. A $\dfrac{1}{2}$
2. B $\dfrac{2}{1}$
3. C $\dfrac{2}{3}$
4. D $\dfrac{3}{2}$

Three solid conductors ab, bc, cd are made of the same metal, have the same length (ℓ) and uniform cross-sections, and their cross-sectional areas are 3A, 2A and A, respectively, as in the opposite figure. The ratio between:
the potential differences $\left(\frac{V_{bc}}{V_{ad}}\right)$ equals ..........

1. A $\dfrac{11}{3}$
2. B $\dfrac{3}{11}$
3. C $\dfrac{5}{22}$
4. D $\dfrac{22}{5}$

In the electric circuit shown in the figure, given that the potential of the earthed point = zero, then ..........

1. A I = $\dfrac{1}{2}$ A, potential of point x = 10 V
2. B I = $\dfrac{1}{2}$ A, potential of point x = 5 V
3. C I = 1 A, potential of point x = 5 V
4. D I = 1 A, potential of point x = 10 V

The opposite figure shows a closed electric circuit. When the rheostat (S) is doubled, the voltmeter reading ..........

1. A increases but does not reach double its first value
2. B doubles
3. C decreases but does not reach half its first value
4. D decreases to half

Which of the following graphs represents the relation between the voltmeter reading and the value of the rheostat S in the opposite electric circuit?

1. A A
2. B B
3. C C
4. D D

Which of the following graphs represents the relation between the reading of voltmeter $V_1$ and the reading of voltmeter $V_2$ when the value of the rheostat R in the opposite electric circuit is changed? (Note: $V_1$ and $V_2$ are drawn to the same scale)

1. A A
2. B B
3. C C
4. D D

Figure (1) represents graphically the relation between the current (I) in the circuit shown in figure (2) and the reading of voltmeter $(V_1)$ in it.
Which of the following can be a possible value of the readings of the ammeter (A) and the voltmeter $(V_2)$ at different values of the rheostat?

1. A Ammeter 1 A, voltmeter $V_2$ 2 V
2. B Ammeter 0.8 A, voltmeter $V_2$ 8 V
3. C Ammeter 0.6 A, voltmeter $V_2$ 3 V
4. D Ammeter 0.5 A, voltmeter $V_2$ 10 V

Which of the following graphs represents the relation between the total current (I) in the circuit shown in the opposite figure and the potential difference (V) across each of the three resistors x, y, z?

1. A A
2. B B
3. C C
4. D D

Graph (1) represents the electric potential differences across the parts of the electric circuit shown in figure (2). From your study of figures (1) and (2):
the ammeter reading equals ..........

1. A 1 A
2. B 2 A
3. C 3 A
4. D 4 A

Graph (1) represents the electric potential differences across the parts of the electric circuit shown in figure (2). From your study of figures (1) and (2):
the value of resistance R is ..........

1. A 10 Ω
2. B 9 Ω
3. C 6 Ω
4. D 4 Ω

In the electric circuit shown, when only switch $S_1$ is closed the voltmeter reading is $V_1$, when only switch $S_2$ is closed the voltmeter reading is $V_2$, and when both switches $S_1$ and $S_2$ are closed the voltmeter reading is $V_3$. Then ..........

1. A $V_3 > V_2 > V_1$
2. B $V_2 > V_1 > V_3$
3. C $V_3 > V_1 > V_2$
4. D $V_1 > V_2 > V_3$

In the opposite electric circuit, the readings of the two voltmeters $(V_1)$ and $(V_2)$, respectively, are ..........

1. A $V_1$ = 0, $V_2$ = 0
2. B $V_1$ = 0, $V_2$ = 30 V
3. C $V_1$ = 30 V, $V_2$ = 30 V
4. D $V_1$ = 30 V, $V_2$ = 60 V

In the electric circuit shown, four lamps are lit. If lamp X burns out, how many lamps stay lit?

1. A 0
2. B 1
3. C 2
4. D 3

In which of the following electric circuits does one of the two lamps light up when both switches are closed?

1. A A
2. B B
3. C C
4. D D

In the electric circuit shown in the figure, when switch K is closed, the brightness of each of lamps a and b ..........

1. A Lamp a: increases, lamp b: decreases
2. B Lamp a: goes out, lamp b: increases
3. C Lamp a: increases, lamp b: increases
4. D Lamp a: goes out, lamp b: decreases

In the opposite electric circuit, given that the four lamps A, B, C, D are identical, what happens to the brightness of lamps A and B when switch K is closed?

1. A Lamp A: increases, lamp B: decreases
2. B Lamp A: stays constant, lamp B: increases
3. C Lamp A: stays constant, lamp B: decreases
4. D Lamp A: decreases, lamp B: increases

Six identical lamps, a DC source and a switch (K) are connected together as in the opposite figure:
the number of lit lamps when switch (K) is open is ..........

1. A 3
2. B 4
3. C 5
4. D 6

Six identical lamps, a DC source and a switch (K) are connected together as in the opposite figure:
the number of lit lamps when switch (K) is closed is ..........

1. A 3
2. B 4
3. C 5
4. D 6

Six identical lamps, a DC source and a switch (K) are connected together as in the opposite figure:
what happens to the brightness of lamps x and y, respectively, when switch (K) is closed?

1. A Lamp x: increases, lamp y: does not change
2. B Lamp x: increases, lamp y: increases
3. C Lamp x: decreases, lamp y: increases
4. D Lamp x: does not change, lamp y: decreases

In the opposite electric circuit, two rods x and y of the same metal have the same length, and the cross-sectional area of y is double that of x. They are connected together by a copper slider S. If the slider moves in the direction shown in the figure, the brightness of the lamp ..........

1. A increases
2. B decreases until it goes out
3. C does not change
4. D decreases but does not go out

In the opposite electric circuit, when the slider is at the middle of resistance wire XY, the two identical lamps (1) and (2) are equally bright. If the slider is moved a little towards X, what happens to the brightness of the two lamps?

1. A Lamp (1): increases, lamp (2): increases
2. B Lamp (1): increases, lamp (2): decreases
3. C Lamp (1): decreases, lamp (2): increases
4. D Lamp (1): decreases, lamp (2): decreases

In the circuit shown, rod XY has a resistance of 10 Ω and two identical lamps A and B each have a resistance of 10 Ω. What happens to the brightness of lamps A and B while the slider P moves from its position towards point Y?

1. A Lamp A: does not change, lamp B: increases
2. B Lamp A: increases, lamp B: increases
3. C Lamp A: decreases, lamp B: does not change
4. D Lamp A: increases, lamp B: decreases

In the opposite electric circuit, which of the variable resistors shown increases the brightness of the lamp when its value is increased?

1. A Resistor $(R_1)$
2. B Resistor $(R_2)$
3. C Resistor $(R_3)$
4. D Resistor $(R_4)$

In the opposite electric circuit, what happens to the brightness of the lamp and the voltmeter reading when the slider is moved from P to Q?

1. A Lamp brightness: increases, voltmeter reading: decreases
2. B Lamp brightness: increases, voltmeter reading: increases
3. C Lamp brightness: does not change, voltmeter reading: decreases
4. D Lamp brightness: does not change, voltmeter reading: increases

Two lamps (1) and (2) of resistances $R_1$ and $R_2$, respectively, are connected together in series with an electric source. If $R_1 < R_2$, then ..........

1. A Lamp (1) is brighter
2. B Lamp (2) is brighter
3. C The two lamps are equally bright
4. D The answer cannot be determined

Two lamps (1) and (2) of resistances $R_1$ and $R_2$, respectively, are connected together in parallel with an electric source. If $R_1 > R_2$, then ..........

1. A Lamp (1) is brighter
2. B Lamp (2) is brighter
3. C The two lamps are equally bright
4. D The answer cannot be determined

In the electric circuit shown in the figure, an electric lamp is marked (30 V, 45 W). The value of resistance R that makes the lamp light at its rated voltage and power equals ..........

1. A 1.5 Ω
2. B 10 Ω
3. C 15 Ω
4. D 67.5 Ω

In the opposite electric circuit, if the electric power consumed in the 12 Ω and 2 Ω resistors is 48 W and 32 W, respectively, the electric power consumed in resistor (R) equals ..........

1. A 16 W
2. B 64 W
3. C 75 W
4. D 81 W

Three resistors x, y, z of values R, 2R and 0.5R, respectively, are connected together in series in a closed electric circuit. The ratio of the power consumed in them $(P_w)_x : (P_w)_y : (P_w)_z$, respectively, is ..........

1. A $4 : 2 : 1$
2. B $2 : 3 : 1$
3. C $2 : 4 : 1$
4. D $2 : 3 : 4$

In the circuit shown, if the power consumed in resistor R is 12 W and $I_1 = 2$ A, then:
the potential difference across the battery equals ..........

1. A 24 V
2. B 12 V
3. C 6 V
4. D 3 V

In the circuit shown, if the power consumed in resistor R is 12 W and $I_1 = 2$ A, then:
the total current in the circuit equals ..........

1. A $\dfrac{4}{3}$ A
2. B $\dfrac{13}{3}$ A
3. C $\dfrac{7}{3}$ A
4. D 1 A

In the circuit shown, if the power consumed in resistor R is 12 W and $I_1 = 2$ A, then:
the value of resistance R equals ..........

1. A 24 Ω
2. B 18 Ω
3. C 12 Ω
4. D 9 Ω

When two resistors R and 4R are connected in parallel with a battery, the power consumed in resistor R is .......... the power consumed in resistor 4R

1. A four times
2. B double
3. C equal to
4. D a quarter of

Two resistors 10 Ω and R: the power consumed in them when connected together in parallel with a battery of negligible internal resistance is four times the power consumed in them when connected together in series with the same battery. The value of R equals ..........

1. A 10 Ω
2. B 7.5 Ω
3. C 5 Ω
4. D 2.5 Ω

Two conductors of the same metal are connected together in parallel to a potential difference of 220 V. If the length of the first conductor is double that of the second and the diameter of the first is double that of the second, the ratio between the power consumed in the two conductors $\left(\frac{(P_w)_1}{(P_w)_2}\right)$ equals ..........

1. A $\dfrac{4}{1}$
2. B $\dfrac{2}{1}$
3. C $\dfrac{1}{2}$
4. D $\dfrac{1}{4}$