Home › MCQs › JEE MAIN Physics › Question #983
Back to Questions
JEE MAIN Physics QUESTION #983
Question 1
A small rigid spherical ball of mass \(M\) is dropped in a long vertical tube containing glycerine. The velocity becomes constant after some time. If the density of glycerine is half the density of the ball, then the viscous force acting on the ball is:
  • 2Mg
  • Mg
  • \(\dfrac{3}{2}Mg\)
  • \(\dfrac{Mg}{2}\)✔️
Correct Answer Explanation
At terminal velocity: Viscous force \(= W - F_b\). Buoyancy \(F_b = \rho_{glycerine} \cdot V \cdot g = \frac{1}{2}\rho_{ball} \cdot V \cdot g = \frac{Mg}{2}\). So Viscous force \(= Mg - \frac{Mg}{2} = \frac{Mg}{2}\).