Home/
Competitive Exams/
JEE Main & Advanced/
Physics/
Circular Motion/
Question 30675
JEE Physics · Hard

Circular Motion: Advanced — Minimum Coefficient for Loop MCQ

Solve this quality-checked JEE multiple-choice question, then review the correct answer and explanation.

Timer-based practiceDetailed answer reviewMobile-friendly flow
Advanced — Minimum Coefficient for LoopHardQuestion 30675

Question

What minimum speed at the bottom of a vertical loop (radius R) is needed for a block on the inside of the loop to stay on the track at the top?
  1. A
    √(gR)
  2. B
    √(5gR)
    Correct
  3. C
    √(3gR)
  4. D
    √(2gR)

Correct answer

√(5gR)

Explanation

At the top, minimum condition: N = 0, mg = mv_top²/R → v_top = √(gR). Energy: ½mv_bottom² = ½mv_top² + mg×2R → v_bottom_min = √(v_top²+4gR) = √(gR+4gR) = √(5gR).

Review Circular Motion notesStart timed chapter practice