Chapter 10

A Black Hole has mass MBH = 15 MSolar. What is its Schwarzschild radius?

• 50.5 km

• 44.24 km

• 76 km

• 100 km

A Black Hole has mass MBH = 1800MSolar. What is its Schwarzschild radius?

• 150.5 km

• 444.24 km

• 5309.32 km

• 8769.60 km

If the Schwarzschild radius of a Black Hole is 10 km, what is its mass?

• 15 Msolar

• 6.8 Msolar

• 35 Msolar

• 48 Msolar

Why black holes are black?

• Because they do not have any energy

• Because nothing escapes

• Because radiation does not escape

• Because light does not escape

What is at the center of a black hole?

• Another black hole

• A little galaxy

• The singularity point

• An X-ray source

What is a supermassive black hole?

• Black hole with mass similar to the sun

• Black hole with mass similar to Jupiter

• Black hole with mass similar to 3Msolar

• Black hole with mass (thousand - billion) Msolar

How did the Black Holes were predicted?

• By observation

• With radio telescopes

• With optical telescopes

• Mathematically using Einstein’s general relativity theory

Hawking radiation is black body radiation due to

• Electromagnetic effects

• Quantum effects

• Gravity effects

• Mechanical effects

Where is the Hawking radiation emitted?

• Near the singularity

• Near the horizon

• Near the Schwarzschild radius

• From particles orbiting the black hole

Two Black Holes have the following masses M1 = 100 Msolar and M2 = 40 Msolar . Show that Schwarzschild radius of the first black hole satisfies one of the relations given below. (Do not panic this is a really easy question!!. Hint: All you need is the relation that gives the Schwarzschild radius of a black hole. Look at the lecture slides.)