NEET Solved Paper 2018 Question 42
Question: A 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 [NEET - 2018]
Options:
A) $ {r^{5}} $
B) $ {r^{2}} $
C) $ {r^{3}} $
D) $ {r^{4}} $
Show Answer
Answer:
Correct Answer: A
Solution:
Power $ \text{=6}\pi \eta rV _{T}\cdot V _{T}=6\pi \eta rV_T^{2} $
$ V _{T}\propto r^{2} $
$ \Rightarrow \text{Power }\propto {r^{5}} $
