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When a resistance of 2 ohm is connected ...

When a resistance of 2 ohm is connected across terminals of a cell, the current is `0.5 A`. When the resistance is increased to 5 ohm, the current is `0.25 A` The e.m.f. of the cell is

A

1.0 V

B

1.5 V

C

2.0 V

D

2.5 V

Text Solution

Verified by Experts

The correct Answer is:
B
Use `E = I (R +r)`
`E= 0.5 ( 2+r) …….(1) `
`E=0.25 (5 +r) …(2)`
by eq ` (1) & (2) E= 1.5 V `
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