12 Light – 2020N

A man sees a stone at the bottom of a pool of water.

Which path could be taken by light from the stone to the man?

Which statement about a thin converging lens is correct?

• All rays of light refracted by the lens pass through the principal focus.

• All rays initially parallel to the principal axis of the lens are refracted through the principal focus.

• The focal length of the lens is the distance between the image and the principal focus.

• The focal length of the lens is the distance between the object and the image.

The diagram shows a beam of white light passing through a triangular prism. A spectrum is produced.

Which row correctly shows a wave property involved in producing the colours at X and Y, and colours of X and Y?

• diffraction - red - violet

• dispersion - red - violet

• reflection - violet - red

• refraction - violet - red

Which diagram shows the image correctly formed by reflection?

White light can be split into different colours by passing it through a prism.

What is the name of this process?

• diffraction

• dispersion

• reflection

• total internal reflection

A boy is having his eyes tested. A letter is printed on a card placed over his head. He sees the card in a plane mirror placed on the far wall of the room.

He sees the letter 'R' in the mirror.

How is it printed on the card?

The diagram shows the image made by a converging lens.

Which statement describes the image formed?

• diminished and inverted

• diminished and upright

• enlarged and inverted

• enlarged and upright

The diagram shows white light passing through a prism.

Which description of what happens as the light passes into the prism is correct?

• The speed of the red light is less than the speed of the violet light and the red light is the least refracted.

• The speed of the red light is greater than the speed of the violet light and the red light is the least refracted.

• The speed of the violet light is less than the speed of the red light and the violet light is the least refracted.

• The speed of the violet light is greater than the speed of the red light and the violet light is the least refracted.

An optical lever is a very sensitive device for detecting small rotations. A lamp sends a narrow beam of light on to a small plane mirror attached to a shaft whose rotation is to be measured. The operation of the device is shown in plan view.

The beam from the lamp reflects from the mirror to give a small spot of light on a scale placed just above the lamp. The shaft and mirror rotate through 1°. The spot of light moves along the scale.

The table shows the angle θ through which the reflected beam rotates and the conditions required for high sensitivity.

Which row is correct for angle θ and to achieve high sensitivity?

• 1°, the lamp and scale need to be as close to the mirror as possible

• 1°, the lamp and scale need to be as far from the mirror as possible

• 2°, the lamp and scale need to be as close to the mirror as possible

• 2°, the lamp and scale need to be as far from the mirror as possible

A student draws a diagram to illustrate the different sections of a longitudinal wave.

Which labelled section is a rarefaction?