RRB Technician 2014 Ques 21
Question: A hot body will radiate heat most rapidly if its surface is
Options:
A) white and rough
B) white and polished
C) black and rough
D) black and polished
Show Answer
Answer:
Correct Answer: C
Solution:
- Radiation is greater from a rough surface because its effective area is greater than its geometric area. Black colour is a good radiator. Hence, black and rough surface shall radiate heat rapidly.
BETA
