If star A has a temperature that is twice as hot as the Sun but has the same luminosity as the Sun, the diameter of star A must be _________ times the diameter of the Sun.
A) 16
B) 4
C) 2
D) 1/2
E) 1/4

Question

Quizplus · Accepted Answer

The luminosity of a star is proportional to the square of its radius and the fourth power of its temperature. If star A has the same luminosity as the Sun but twice the temperature, its radius must be smaller by a factor of 4 to compensate for the increased temperature, making its diameter 1/4 times that of the Sun.

If Star a Has a Temperature That Is Twice as Hot