JEE Main · 2022 · 27 Jul 2022 · Shift 1 · Current Electricity

In meter bridge experiment for measuring unknown resistance 'S', the null point is obtained at a distance 30 cm from the left side as shown at point

D

. If

R

5.6 k Ω

, then the value of unknown resistance 'S' will be ______

Ω

Answer: 2400

Solution

In a meter bridge, at null point:

S / l_{1} = R / l_{2}

where

l_{1} = 30

cm and

l_{2} = 70

cm. Given

R = 5.6 \times 1 0^{3} Ω

, we have

S = R \times (l_{1} / l_{2}) = 5600 \times (30/70) = 5600 \times (3/7) = 2400Ω

JEE Main · 2022 · 27 Jul 2022 · Shift 1 · Integer answer