OnlineCBT
Physics · PYQ NEET UG 2018
हिन्दीA small sphere of radius 'r' falls from rest in a viscous liquid. As a result, heat is produced due to viscous force. The rate of production of heat when the sphere attains its terminal velocity, is proportional to
Correct answer · Option 3
\( r^5 \)
Explanation
Rate of heat production = Power dissipated = \( F_v \cdot v_t \). Since \( F_v = 6\pi\eta r v_t \) and \( v_t \propto r^2 \), power \( P \propto r \cdot r^2 \cdot r^2 = r^5 \).
