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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