Star A has surface temperature and radius

PHYSICS · Single correct · AP · Physics 2: Algebra-based · Modern Physics · Modern Physics

Problem

Star A has surface temperature

6000\;\text{K}

and radius

R

. Star B has surface temperature

8000\;\text{K}

and radius

0.5R

. Treating both stars as perfect blackbodies, what is the ratio of their total radiant powers (luminosities)

\dfrac{P_B}{P_A}

? (a) 1.58 (b) 0.79 (approximately) (c) 0.44 (d) 1.33