This relates the transmitted intensity I to the incident intensity I ∘ when polarised light is incident and then transmitted through an analyser. The relation is I = I ∘ cos 2 θ where θ is the angle between the transmission axis and the direction of the incident electric field.

Physics for the IB Diploma 6th Edition>Chapter 4 - Waves>Test yourself>Q 21

MEDIUM

Diploma

IMPORTANT

Earn 100

Suggest why only transverse waves can be polarised.

Important Questions on Waves

MEDIUM

Diploma

IMPORTANT

Physics for the IB Diploma 6th Edition>Chapter 4 - Waves>Test yourself>Q 23

State Malus’s law.

MEDIUM

Diploma

IMPORTANT

Physics for the IB Diploma 6th Edition>Chapter 4 - Waves>Test yourself>Q 23

Polarised light is incident on a polariser whose transmission axis makes an angle of

25 °

with the direction of the electric field of the incident light. Calculate the fraction of the incident light intensity that is transmitted through the polariser.

MEDIUM

Diploma

IMPORTANT

Physics for the IB Diploma 6th Edition>Chapter 4 - Waves>Test yourself>Q 27

A ray of light is incident on a rectangular block of glass of refractive index $1.450$ at an angle of $40 °$ , as shown in the diagram. The thickness of the block is $4.00 cm$ . Calculate the amount $d$ by which the ray is deviated.

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MEDIUM

Diploma

IMPORTANT

Physics for the IB Diploma 6th Edition>Chapter 4 - Waves>Test yourself>Q 28

The speed of sound in air is

340 m s^{- 1}

and in water it is

1500 m s^{- 1}

. Determine the angle at which a beam of sound waves must hit the air–water boundary so that no sound is transmitted into the water.

MEDIUM

Diploma

IMPORTANT

Physics for the IB Diploma 6th Edition>Chapter 4 - Waves>Test yourself>Q 29

Planar waves of wavelength

1.0 cm

approach an aperture whose opening is also

1.0 cm

. Draw the wavefronts of this wave as they emerge through the aperture.

HARD

Diploma

IMPORTANT

Physics for the IB Diploma 6th Edition>Chapter 4 - Waves>Test yourself>Q 31

A radio station, $R$ , emits radio waves of wavelength $1600 m$ which reach a house, $H$ , directly and after reflecting from a mountain, $M$ , behind the house (see diagram). The reception at the house is very poor. Estimate the shortest possible distance between the house and the mountain. (Pay attention to phase changes.)

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