Question

In a metre bridge experiment , resistance box with 2 Ω is connected in the left gap and the unknown resistance S in the right gap. If the balancing length be 40 cm, value of S will be *

(a) 2 Ω

(b) 3 Ω

(c) 4 Ω

(d) 5 Ω​

Answer 1

Answer:

let unknown resistance be X

so by meter bridge formula

X=R×L1 / (100-L1)

If balancing length =40 then L1 will be 100-40=60

X=2×60/40

X=120/40

X=3 ohm

So correct option is B

Hope it helps