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If specific resistance of a potentiometer wire is 10–7 Ωm, the current flow through it is 0.1 A and the cross-sectional area of wire is 10–6 m2 then potential gradient will be
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- 10–2 volt/m
- 10–4 volt/m
- 10–6 volt/m
- 10–8 volt/m
Correct Option: A
Potential gradient = Potential fall per unit length. In this case resistance of unit length.
| R = | ρl | = | 10-7 x 1 | = 10 -1Ω |
| A | 10-6 |
Potential fall across R is
V = I.R = 0.1 x 10-1 = 0.01 volt/m.
= 10-2 volt/m
