In the circuit shown, a four-wire potentiometer is made of a 400 cm long wire, which extends between A and B. The resistance per unit length of the potentiometer wire is ` r = 0.01 Omega //cm`. If an ideal voltmeter is connected as shown with jockey `J` at 50 cm from end A, the expecteed reading of the voltmeter will be _______ volts.

Options

A. 0.25V
B. 0.75V
C. 0.50V
D. 0.20V

Explanation

`i=V/R_(eq)=3/6=0.5A , Delta V_AJ)=JR_(AJ)=(0.5)(0.5)=0.25V`