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

Current Electricity

(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

Numerical

(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
Current Electricity
(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

Numerical

(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.

Numerical

(a)   11R/12

(b) 13R/12

(c)   R/5

(d) 15R/12

Ans: (c)