CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon


Question

The resistivity of potentiometer wire is $$40\times 10^{-8}ohm$$ - metre and its area of cross-section is $$8\times 10^{-6}m^{2}$$. If $$0.2$$ ampere current is flowing through the wire, the potential gradient of the wire is:


A
101V/m
loader
B
102V/m
loader
C
103V/m
loader
D
104V/m
loader

Solution

The correct option is B $$10^{-2}V/m$$
Given :  $$\rho = 40\times 10^{-8} ohm-m$$    $$I = 0.2 $$ A   $$A = 8 \times 10^{-6} m^2$$
Resistance of the wire  $$R = \rho \dfrac{L}{A}$$
Potential difference across the wire  $$V = IR  = I\rho \dfrac{L}{A}$$
Thus potential gradient of the wire  $$\dfrac{V}{L} = \dfrac{I\rho}{A}$$
$$\therefore$$  $$\dfrac{V}{L} = \dfrac{0.2 \times 40\times 10^{-8}}{8\times 10^{-6}}$$  
$$\implies$$  $$\dfrac{V}{L} = 10^{-2} V/m$$

Physics

Suggest Corrections
thumbs-up
 
0


similar_icon
Similar questions
View More


similar_icon
People also searched for
View More



footer-image