## Two cells of emf E1 and E2 (E1 > E2) are connected as shown in figure. When a potentiometer is connected between…..

Q. Two cells of emf E1 and E2 (E1 > E2) are connected as shown in figure.
When a potentiometer is connected between A and B, the balancing length of the potentiometer wire is 300cm. On connecting the same potentiometer between A and C, the balancing length is 100cm. The ratio E1/E2 is (a) 3 : 1
(b) 1 : 3
(c) 2 : 3
(d) 3 : 2

Ans: (d)

## A, B, and C are voltmeters of resistance R, 1.5R, and 3R, respectively. When some potential difference is…..

Q. A, B, and C are voltmeters of resistance R, 1.5R, and 3R, respectively. When some potential difference is applied between X and Y, the voltmeter readings are VA, VB, and VC, respectively. Then (a) VA = VB = VC

(b) VA ≠ VB = VC

(c) VA = VB ≠ VC

(d) VB ≠ VA = VC

Ans: (a)

## A candidate connects a moving coil voltmeter V, a moving coil ammeter A, and a resistor R as shown in figure…..

Q. A candidate connects a moving coil voltmeter V, a moving coil ammeter A, and a resistor R as shown in figure. If the voltmeter reads 20 V and the ammeter reads 4A, R is (a) equal to 5Ω
(b) greater than 5Ω
(c) less than 5Ω
(d) greater or less than 5Ω depending upon its material

Ans: (b)

## A cell of emf E volt with no internal resistance is connected to a wire whose cross section changes. The wire has…..

Q. A cell of emf E volt with no internal resistance is connected to a wire whose cross section changes. The wire has three sections of equal length. The middle section has a radius a, whereas the radius of the outer two sections is 2a. The ratio of the potential difference across section AB to the potential difference across section CA is (a) 5

(b) 4

(c) 1/2

(d) 1/4

Ans: (b)

## The circuit shown has resistors of equal resistance R. Find the equivalent resistance between A and B, when the key is closed.

Q. The circuit shown has resistors of equal resistance R. Find the equivalent resistance between A and B, when the key is closed. (a)   11R/12

(b) 13R/12

(c)   R/5

(d) 15R/12

Ans: (c)