Question 689: Current Electricity

Question

If specific resistance of a potentiometer wire is 10
-7
$\Omega $ m and current flow through it is 0.1 amp., cross-sectional area of wire is 10
$-$6
m
2
then potential gradient will be

Accepted Answer

Potential gradient = Potential fall per unit length. In this case resistance of unit length.
$R = {{ho l} \over A} = {{{{10}^{ - 7}} 	imes 1} \over {{{10}^{ - 6}}}} = {10^{ - 1}}\Omega $
Potential fall across R is
V = I.R = 0.1 $ 	imes $ 10
-1
=  0.01volt/m.
$ = {10^{ - 2}}$ volt/m

Answer

10
$-$2
volt/m

Answer

10
$-$4
volt/m

Answer

10
$-$6
volt/m

Answer

10
$-$8
volt/m.

Current Electricity

If specific resistance of a potentiometer wire is 10 -7 \Omega m and current flow through it is 0.1 amp., cross-sectional area of wire is 10 -6 m 2 then potential gradient will be

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