Concepts

Question 1

Explain why the alpha particles have discrete energies

Answer 1

The conservation of momentum dictates that the alpha particle would be emitted in the opposite direction of the daughter nuclide. The daughter nucleus can only take on discrete momentum value, in other words, discrete velocity, so the alpha particle will also have discrete energy.

Question 2

Rank the fundamental interactions in order of increasing strength

Answer 2

Gravity, Weak Nuclear, Electromagnetic, Strong Nuclear

Question 3

Rank the fundamental interactions in order of increasing range

Answer 3

Weak Nuclear, Strong Nuclear, Electromagnetic/ Gravity

Question 4

Rank the radiations in order of increasing penetrative power

Answer 4

Alpha, Beta, Gamma

Question 5

Rank the radiations in order of increasing ionizing power

Answer 5

Gamma, Beta, Alpha

Question 6

How to calculate critical angle?

Answer 6

arcsin( speed of light in medium / speed of light in vacuum)

Question 7

Why is the core of a transformer made of iron?

Answer 7

It is to reduce the loss of flux linkage by concentrating the magnetic flux within itself.

Question 8

What are the advantages of thin film on lens?

Answer 8

• Glare from lens is reduced
• Energy reaching the sensor is increased
• Waves travel at the same wavelength