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Friday, 9 October

JEE Main 2021 · PhysicsMultiple choiceSingle correctMediumMulti-step

JEE Main 18 March 2021, Shift 1, Physics Q1

Question 1 of 90 in this shift, Physics question 1 of 30, Section A.

An oil drop of radius 2 mm with a density 3 g cm−3^{-3} is held stationary under a constant electric field 3.55×1053.55\times10^{5} V m−1^{-1} in the Millikan's oil drop experiment. What is the number of excess electrons that the oil drop will possess ? Consider g=9.81g = 9.81 m/s2^2
  1. (1)17.3×101017.3\times10^{10}
  2. (2)1.73×10101.73\times10^{10}Official answer
  3. (3)1.73×10121.73\times10^{12}
  4. (4)48.8×101148.8\times10^{11}

Official answer

Option 2

NTA final key.

Topic
No close match in our taxonomy
Idea tested
No close match in our taxonomy

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.