A) \[{{10}^{-2}}\,V/m\]
B) \[{{10}^{-4}}\,V/m\]
C) 0.1 V/m
D) 10 V/m
Correct Answer: A
Solution :
Key Idea: Potential gradient of a wire is equal to potential fall per unit length. Potential gradient = Potential fall per unit length = Current \[\times \] Resistance per unit length \[=i\times \frac{R}{l}\] but \[R=\frac{\rho l}{A}\] \[\Rightarrow \] \[\frac{R}{l}=\frac{\rho }{A}\] \[\therefore Potential\,graident\,=i\times \frac{\rho }{A}\] Here, \[\rho ={{10}^{-7}}\,\Omega -m,\,\,i=0.1\,A,\,A={{10}^{-6}}\,{{m}^{2}}\] Hence, potential gradient = \[0.1\times \frac{{{10}^{-7}}}{{{10}^{-6}}}=\frac{0.1}{10}\] \[=0.01={{10}^{-2}}\,V/m\]
You need to login to perform this action.
You will be redirected in
3 sec
