Chapter 33, Problem 10RAT

A black hole is

(a) an empty region of space with a huge gravitational field.

(b) a small region that has the mass of many galaxies.

(c) the remains of a supergiant collapsed star.

(d) as large as its photon sphere.

To determine

The correct option for the statement “A black hole is”.

Answer to Problem 10RAT

The correct option for the statement “A black hole is” is option (c).

Explanation of Solution

A part of space containing matter where the gravitational field is extremely high that no particle could leave the field is called a black hole. A black hole is formed when a giant superstar cave in to reach infinite densities due to strong gravitational pull. Thus, it is the remains of a supergiant collapsed star.

All the mass of a star collapses into a small region of infinite densities when the black hole is formed. Thus, a black hole contains matter. It is not an empty space.

Black holes can have different masses depending on the mass of the star from which it collapsed. It does not always have the mass of galaxies.

The photon sphere is an orbit around the black hole where photons move in circles. It is a region above the black hole where some light can still be able to escape.

Conclusion:

Therefore, the correct option for the statement “A black hole is” is option (c).