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Friday, 9 October

JEE Main 2020 · PhysicsMultiple choiceDiagram basedMediumMulti-step

JEE Main 2 September 2020, Shift 1, Physics Q4

Question 4 of 75 in this shift, Physics question 4 of 25.

A bead of mass mm stays at point P(a,b)P(a, b) on a wire bent in the shape of a parabola y=4Cx2y=4Cx^{2} and rotating with angular speed ω\omega (see figure). The value of ω\omega is (neglect friction) :

The figure, in words

Parabola y=4Cx^2 opening upward about the y-axis (rotation axis, angular speed omega); bead at point P(a,b) on the right branch with dashed projections to the axes; origin O.
  1. (1)22gC2\sqrt{2gC}Official answer
  2. (2)2gC\sqrt{\frac{2g}{C}}
  3. (3)2gCab\sqrt{\frac{2gC}{ab}}
  4. (4)2gC2\sqrt{gC}

Official answer

Option 1

NTA final key (Sep 2020).

Chapter
Laws of Motion
Topic
Circular Motion
Idea tested
Bead on a Rotating Hoop

Same topic in other shifts

All Circular Motion questions
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  6. 31 Jan 2024, Shift 1 · Q33A coin is placed on a disc. The coefficient of friction between the coin and the disc is μ\mu. If the distance of the coin from the…EasySingle correct

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. This question needs a figure we do not reproduce; it is described in words above. Lumi analyses 42 of the 174 JEE Main shifts held from 2017 to 2026.