question_answer

A potentiometer consists of a wire of length 4 m and resistance \[10\,\,\Omega \]. It is connected to a cell of emf 2V. The potential gradient of wire is:                                                                                               [AIPMT 1999]

A) 0.5 V/m 

B)                   2 V/m C)  5 V/m   D)       10 V/m Correct Answer: A Solution : [a] Potential gradient \[\text{=}\frac{\text{Potential}\,\text{applied}}{\text{Length}\,\text{of}\,\text{wire}}\]

\[\therefore \]      \[k=\frac{V}{L}\]

Given, \[V=2\text{ }V,L=4\,m\]

\[\therefore \]      \[k=\frac{2}{4}=0.5\,V/m\]