Question

In a potentiometer circuit there is a cell of e.m.f. 2 volt, a resistance of 5 ohm and a wire of uniform thickness of length 1000 cm and resistance 15 ohm. The potential gradient in the wire is

• A. $\frac { 1 } { 500 } \mathrm {~V} / \mathrm { cm }$
• B. $\frac { 3 } { 2000 } \mathrm {~V} / \mathrm { cm }$
• C. $\frac { 3 } { 5000 } \mathrm {~V} / \mathrm { cm }$
• D. $\frac { 1 } { 1000 } \mathrm {~V} / \mathrm { cm }$

Answer 1

Answer: (B)

$\frac { 3 } { 2000 } \mathrm {~V} / \mathrm { cm }$

Answer 2

Potential gradient $x = \frac { V } { L } = \frac { i R } { L }$

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