Current Electricity Charging Discharging Of Capacitors Question 235
Question: . The resistivity of a potentiometer wire is $ 40\times {{10}^{-8}},ohm-m $ and its area of cross-section is $ 8\times {{10}^{-6}},m^{2} $ . If 0.2 amp current is flowing through the wire, the potential gradient will be
[MP PMT/PET 1998]
Options:
A) $ {{10}^{-2}},volt/m $
B) $ {{10}^{-1}},volt/m $
C) $ 3.2\times {{10}^{-2}},volt/m $
D) $ 1,volt/m $
Show Answer
Answer:
Correct Answer: A
Solution:
Potential gradient $ =\frac{V}{L}=\frac{iR}{L}=\frac{i\rho L}{AL}=\frac{i\rho }{A} $
$ =\frac{0.2\times 40\times {{10}^{-8}}}{8\times {{10}^{-6}}}={{10}^{-2}},V/m $
BETA
