# Three and four mark questions

These are similar to one and two mark questions but you will be expected to write in more depth for three and four mark questions.

Three and four mark questions usually require longer answers.

This page contains AQA material which is reproduced by permission of AQA.

## Sample question 1 - Foundation

Question

The signals for a baby monitor unit are transmitted as electromagnetic waves with a wavelength of 0.125 m.

Wave speed of electromagnetic waves = 3 × 108 m/s

Calculate the frequency of the signal. [3 marks]

Wave speed = frequency × wavelength

3 × 108 = frequency × 0.125 [1]

frequency = 3 × 108 ÷ 0.125 [1]

= 2.4 × 109 Hz [1]

## Sample question 2 - Higher

Question

The waves generated on the surface of the water are transverse waves.

Describe the differences between longitudinal waves and transverse waves.

In longitudinal waves, the particles oscillate parallel to the direction of energy transfer, causing areas of compression and rarefaction. In transverse waves, the particles oscillate perpendicular to the direction of energy transfer, causing peaks and troughs. [3]

## Sample question 3 - Higher

Question

A monitor for a baby sleeping in a cot has a sensor unit that transmits an image of the baby and the noises the baby makes to a monitor unit.

The monitor unit then displays an image of the baby and emits the noises the baby makes.

Compare the properties of the waves that transmit images and noises from the monitor unit. [4 marks]

Answers may include any four points from:

• light waves are transverse, whereas sound waves are longitudinal
• light waves travel faster than sound waves
• light waves have a higher frequency than sound waves
• light waves have a shorter wavelength than sound waves
• light waves have perpendicular oscillations, whereas sound waves are parallel to the direction of energy transfer

[4]