Question 1

What is the Chandrasekhar limit ?

Accepted Answer

1.4 Solar masses

Answer

0.8 Solar masses

Answer

3 Solar masses

Answer

4 Solar masses

Question 2

What temperature is required for nuclear fusion to occur?

Accepted Answer

10^7K

Answer

10^14K

Answer

6000k

Answer

10^4K

Question 3

What is the minimum energy of X-ray photons for which could pair production occur?

Accepted Answer

>1.02 MeV

Answer

<0.1 MeV

Answer

> 4 MeV

Answer

0.5-5.0 MeV

Question 4

How does an image intensifier work?

Accepted Answer

X-rays strike a Phosphor screen producing visible light photons which produce electrons at the photocathode

Answer

Using photomultiplier tubes

Answer

Using a contrast medium

Answer

Using a charged-couple device CCD

Question 5

Why can't Carbon dating be used on recently dead samples?

Accepted Answer

The half life of Carbon-14 is 5730 years

Answer

We have burned too many fossil fuels so there is too much radioactive carbon  14

Answer

The material hasn't decomposed fully

Question 6

A capacitor is discharged through an LDR.  How would the graph of Q against t be affected if the light level decreased?

Accepted Answer

The graph would have lower gradient

Answer

The graph would have a higher gradient.

Answer

The graph would reach zero faster

Answer

The graph would take longer to reach zero

Question 7

Which medical imaging technique might use Flourine-18?

Accepted Answer

PET

Answer

MRI

Answer

CAT

Answer

Gamma Camera

Question 8

Why is Olber's  Paradox no longer a paradox?

Accepted Answer

The universe is finite, it was found to be expanding as shown by red shift

Answer

The universe is infinite as shown by cosmic microwave background radiationd

Question 9

Which of the following are fundamental particles known as leptons?

Accepted Answer

A Beta + particle

Answer

A photon

Answer

A Sigma particle

Answer

A proton

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