Question

An ideal battery of 4 v and resistance r are connected in series in the primary circuit of a potentiometer oflength 1 m and resistance 5. The value of r, to give a potential difference of 5 mv across 10 cm of

Answer 1

Answer: 395

Explanation:

Length of wire = L = 1m

Resistance = Rh = 5Ω

Battery = e = 4v

Wherein - x = V/L

i = v/R+5 = 4/R+5.A

for 1m resistance is 5Ω

Therefore for 10cm

R10 = 5×10/100 = 0.5Ω

5×10-³ = ( 4/R+5) × 0.5

( 4/R+5) = 10Ω

R+5 = 400Ω

R = 395Ω

Value of R = 395