The size of a black hole, its Schwarzschild radius, is simply proportional to its _____.
A) mass
B) luminosity
C) temperature
D) density
Question 2
Which of the following is a reason why low-mass stars cannot get very hot when they contract?
A) They are unable to convert gravitational energy into thermal energy.
B) They have limited gravitational energy.
C) They get very hot and hence can ignite several nuclear fuels.
D) They can sustain hydrogen fusion only if their masses are less than 0.08 solar mass.