Physics Circle home Student Login

Home›Chapters›Current Electricity PYQs›Potentiometer›Question 61

JEE Main 2021 (25 Jul, Shift 1) · Potentiometer

Potentiometer question from JEE Main 2021 (25 Jul, Shift 1)

Q61JEE Main 2021 · 25 JUL · SHIFT 1Medium

Potentiometer

In the given figure, there is a circuit of potentiometer of length AB = 10 m. The resistance per unit length is 0.1 Ω\Omega per cm. Across AB, a battery of emf E and internal resistance 'r' is connected. The maximum value of emf measured by this potentiometer is:

Figure

Show answer and solution

Answer: (a)

  1. Wire resistance: 1000 cm×0.1 Ω/cm=100 Ω1000\text{ cm}\times0.1\ \Omega/\text{cm} = 100\ \Omega.
  2. From the figure, driver is 6 V with 20 Ω20\ \Omega: I=6100+20=0.05I = \dfrac{6}{100+20} = 0.05 A.
  3. Maximum measurable emf =VAB=0.05×100=5= V_{AB} = 0.05\times100 = 5 V
  4. So the answer is (a) 5 V.
Report a mistake

More questions on Potentiometer