Question

A DC potentiometer is designed to measure up to 2 V with a slide wire of 800 mm. A Standard cell of emf 1.18V obtains balance at 600 mm. A test cell is seen to obtain balance at 680 mm. The emf of the test cell is

• A. 1.00 V
• B. 1.34 V
• C. 1.50 V
• D. 1.70 V

Answer 1

The correct option is B 1.34 V

$\because$ Balance at 600 mm is corresponding to an emf of 1.18 V.
$\because$ Balance at 680 mm is corresponding to an emf of
$(1.18/600)\times 680=1.34V$