If a star has a temperature twice as hot as the Sun's and a luminosity 32 times the Sun's, what is the ratio of its radius to the Sun's radius?

Question

Group of answer choices

2

5.8

16

1/2

Choose the best answer

Answer 1

The luminosity of a star is directly proportional to its radius squared. Therefore, if the luminosity of the star is 32 times that of the Sun, then the radius of the star would be √32 times that of the Sun. Since the temperature of the star is not relevant to the radius, the ratio of the star's radius to the Sun's radius would be √32, which is approximately 5.66. Therefore, the best answer would be 5.8.