polarisation

Question 1

Explain what is meant by a polarised wave.

Answer 1

when the oscillations of a transverse wave are limited to one plane or one direction

Question 2

State the meaning of polarisation.

Answer 2

turning an unpolarised wave into a polarised wave

Question 3

State three methods of polarisation.

Answer 3

• polarising filter
• aerials (receivers)
• reflection

Question 4

State what happens to the energy of a wave when it is polarised.

Answer 4

decreases

Question 5

State the use of polarisation.

Answer 5

reduce glare

Question 6

Ski goggles are used to reduce glare. Which property of glare do ski goggles rely on to be effective$?$

Answer 6

Glare is reflected light, and as a result, it is polarised.

Question 7

State three applications of polarisers.

Answer 7

→ used in sunglasses to cut off unwanted reflected light
→ used to check chirality of organic compounds
→ TV/radio signals
→ 3D cinema glasses

Question 8

Explain how sunglasses reduce glare.

Answer 8

→ reflected light is partially polarised
→ polarising filters in the glasses are oriented at different angles to reduce the glare

Question 9

Explain how tv/radio signals use polarisation.

Answer 9

• broadcasting aerials are horizontally or vertically polarised
• hence receiving aerials need to be aligned in the same plane to receive a strong signal