GCSE Physics  ›  P.6.3 Uses and applications of electromagnetic waves

Uses and applications of electromagnetic waves

Free AQA GCSE Physics practice questions on Uses and applications of electromagnetic waves. Sample questions below with detailed mark schemes — sign up to practise the full set with spaced repetition.

Start free All Physics topics

Compare — 5 marks

A hospital uses two different types of electromagnetic waves for medical imaging. Department A uses infrared radiation to monitor a patient's skin temperature during surgery. Department B uses X-rays to take images of a patient's broken bone.

  1. Compare the wavelengths of infrared radiation and X-rays. [2 marks]
  2. Compare how infrared radiation and X-rays interact with human tissue. [2 marks]
  3. Explain why X-rays are more suitable than infrared radiation for imaging bones inside the body. [1 mark]
Show mark scheme

Calculate — 2 marks

Mobile phones use microwaves to send and receive signals from transmission towers. A mobile phone transmits signals at a frequency of 900 MHz. The speed of microwaves is 3.0 × 10⁸ m/s.

  1. (01.1) Calculate the wavelength of the microwaves. [1 mark]
  2. (01.2) A transmission tower is located 15 km away from the phone. Calculate the time taken for the signal to travel this distance. [1 mark]
Show mark scheme
  • (01.1) λ = v ÷ f or substitution: 3.0 × 10⁸ ÷ 900 000 000
  • (01.1) 0.33 m or 0.3 m
  • (01.2) time = distance ÷ speed or substitution: 15 000 ÷ 3.0 × 10⁸
  • (01.2) 5.0 × 10⁻⁵ s or 0.00005 s

Explain — 3 marks

Satellite dishes receive television signals from communications satellites in space. The satellites transmit microwaves to Earth.

  1. (01.1) Explain why microwaves are used to transmit television signals from satellites. [2 marks]
  2. (01.2) Explain why the satellite dish must be pointed in a specific direction to receive the signal. [1 mark]
Show mark scheme
  • (01.1) microwaves can travel long distances through space
  • (01.1) microwaves penetrate the atmosphere / microwaves can carry large amounts of information
  • (01.2) microwaves travel in straight lines / need line of sight to the satellite

Describe — 2 marks

A student uses a mobile phone to call a friend. The phone sends signals using electromagnetic waves.

  1. (01.1) State the type of electromagnetic wave used to transmit mobile phone signals. [1 mark]
  2. (01.2) Describe one other use of this type of electromagnetic wave. [1 mark]
Show mark scheme
  • (01.1) microwaves
  • (01.2) cooking/heating food (in a microwave oven)
  • (01.2) satellite communications
  • (01.2) radar systems
  • (01.2) WiFi/bluetooth signals

Evaluate — 3 marks

A local council is considering whether to allow a new mobile phone mast to be built in a residential area. The mast would use microwave radiation to improve mobile phone signal for the community. Some residents have expressed concerns about possible health effects from continuous exposure to low-level microwave radiation.

  1. (01.1) State one different use of microwaves. [1 mark]
  2. (01.2) Evaluate whether the council should approve the phone mast. You should consider both the benefits of improved mobile signal and any potential risks from microwave radiation. [2 marks]
Show mark scheme
  • (01.1) Cooking/heating food in microwave ovens
  • (01.1) Satellite communications / satellite TV transmission
  • (01.1) Wi-Fi / Bluetooth technology
  • (01.1) Radar systems for navigation
  • (01.2) Benefit identified: reliable communication / emergency calls / internet access / economic advantages
  • (01.2) Risk identified: microwaves can heat body tissue / concerns about long-term exposure effects
← Previous topic
P.6.2 Electromagnetic waves
Next topic →
P.7.1 Permanent and induced magnetism

Related topics in Physics