AS Exam Questions

Question 1

State and explain how replacing a laser with visible light of a shorter wavelength affect the spacing of the maxima in the screen of an interference pattern

Answer 1

Maxima will be closer together
Because wavelength = w s
—–
D

And when wavelength decreases, fringe spacing decreases

Question 2

Explain why it is important to correctly align the aerial of a tv in order to receive the strongest signal

Answer 2

Transmitted radio waves are often polarised

Aerial rods must be aligned in the same plane as the wave

Question 3

Define ionization

Answer 3

Ionization is the removal or addition of electrons from an atom or molecule

Question 4

State and explain why it is important for car batteries to have a very low internal resistance

Answer 4

Need large current/power to start the car

Internal resistance limits the current and wastes power

Question 5

Sand is placed on the surface of a vibrating plate. Initially the sand stays in contact with plate as it vibrates. The amplitude is constant over the full frequency range of the vibrations. Above a particular frequency the sand grains lose contact with the surface

Explain why (3 marks)

Answer 5

When the vibrating source accelerates DOWN with an acceleration less than the acceleration of free fall the sand stays in contact

Above a particular frequency, the acceleration is greater than g

No contact force on the sand

Question 6

Define tensile stress

Answer 6

The force exerted over CROSS SECTIONAL area