Question

A spherical body of radius 10cm radiates 300 watt at 27 degree Celsius if the radius is doubled and temperature is remain same the power radiated will be
a. 300 W
b. 1200 W
c. 75 W
d. 900 W

Answer 1

power radiated will become 4 times it's initial value power radiated is directly proportional to it's area (r^2)