In a meter bridge, the balancing length from the left end (s... | Physics | SolveeIt | Solveeit

Today, August 18

Question

In a meter bridge, the balancing length from the left end (standard resistance of one ohm is in the right gap) is found to be 20 cm. The value of the unknown resistance is

A

$0.8\, \Omega$

B

$0.5\, \Omega$

C

$0.4\, \Omega$

D

$0.25\, \Omega$

Answer

$0.25\, \Omega$

Explanation

Solution

Metre bridge works on the principle of
Wheatstone bridge.
$\therefore \frac{P}{Q}=\frac{l}{100-l}$ or, $P=\frac{l}{100-l} \times Q$
$= \frac{20}{80} \times 1 = 0.25\, \Omega.$