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Friday, 9 October

JEE Main 2020 · PhysicsMultiple choiceSingle correctMediumCalculation

JEE Main 8 January 2020, Shift 1, Physics Q20

Question 20 of 75 in this shift, Physics question 20 of 25, Section A.

The length of a potentiometer wire is 1200 cm and it carries a current of 60 mA. For a cell of emf 5 V and internal resistance of 20 Ω\Omega, the null point on it is found to be at 1000 cm. The resistance of whole wire is :
  1. (1)60 Ω\Omega
  2. (2)80 Ω\Omega
  3. (3)100 Ω\OmegaOfficial answer
  4. (4)120 Ω\Omega

Official answer

Option 3

NTA final key (Jan 2020).

Chapter
Current Electricity
Topic
Potentiometer
Idea tested
Potential Gradient Calculation

Same idea in other shifts

Asked 2× in all
  1. 28 Jul 2022, Shift 1 · Q55As shown in the figure, a potentiometer wire of resistance 20 Ω\Omega and length 300 cm is connected with resistance box (R.B.) and a…HardNumerical valueHas a figure

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 42 of the 174 JEE Main shifts held from 2017 to 2026.