Heat and Thermodynamics 3 Question 19
19. A spherical black body with a radius of radiates power at . If the radius were halved and the temperature doubled, the power radiated in watt would be
(a) 225
(b) 450
(c) 900
(d) 1800
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Answer:
Correct Answer: 19. (d)
Solution:
- Power radiated
(surface area) . The radius is halved, hence, surface area will become times. Temperature is doubled, therefore, becomes 16 times.
New power