JEE Main 2022 · 24 Jun · Shift 2 · Physics Q53

← JEE Main 2022 · 24 Jun · Shift 2

PhysicsInteger+4 / -1Question 53 of 90

A potentiometer wire of length 10 m and resistance $20\ \Omega$ is connected in series with a 25 V battery and an external resistance $30\ \Omega$ . A cell of emf E in secondary circuit is balanced by 250 cm long potentiometer wire. The value of E (in volt) is $\dfrac x{10}$ . The value of $x$ is ______.

Your answer

Answer and worked solution

Official answer: 25

Current. $I=\dfrac{25}{20+30}=0.5$ A.

Potential gradient. $\dfrac{0.5\times20}{10}=1$ V m $^{-1}$ .

Emf. $E=1\times2.5=2.5$ V $=\dfrac{25}{10}$ , so $x=25$ .

Answer: 25

Topics:Potentiometer

← Previous question Next question →

JEE Main 2022 · 24 Jun · Shift 2, Physics question 53