Electromagnetic Spectrum (Cambridge O Level Physics)

Circle two of the following that apply to an ultrasound wave travelling in air.

Calculate the wavelength of X-rays with frequency 1.3 × 10¹⁷ Hz in a vacuum.

wavelength = ...........................................................

A dentist takes an X-ray photograph of a patient’s teeth. Explain why it is safe for the patient to be close to the source of X-rays, but the dentist must stand away from the source.

State, with a reason, why microwave ovens are designed only to work with the door closed.

Gamma rays are the highest energy waves in the electromagnetic spectrum. 

State the maximum speed of gamma rays in a vacuum.

Calculate the frequency of a gamma ray with a wavelength of 6.5 × 10⁻¹³ m.

Compare and contrast gamma rays and radio waves. You should consider both their properties and their applications.

Gamma rays are dangerous to work with because they transfer large amounts of energy. 

People who work with gamma radiation need to take precautions to keep themselves safe.

Suggest two ways that workers can keep themselves safe when working with gamma rays.

Fig. 1.1 shows a radio wave. Each 1 cm square is equal to 2 m.

A radio wave with a frequency of 20 GHz travels through the vacuum of space. 

Calculate the wavelength of this radio wave.

State why sound waves and radio waves have different frequencies at the same wavelength.

Table 1.1 shows a list of the electromagnetic spectrum.

Table 1.1

Fig. 1.1 shows an X-ray of a broken bone. 

Fig. 1.1

Describe the interaction between the x-rays and 

Fig. 7.1 shows an incomplete diagram of the electromagnetic spectrum.

All electromagnetic waves travel at the same speed in a vacuum.

State one other property that is the same for all electromagnetic waves

For each purpose, state one type of electromagnetic radiation that can be used.

Fig. 7.1 shows some parts of the electromagnetic spectrum.

Fig. 7.1 shows a diagram of the main regions of the electromagnetic spectrum. Two labels are missing.

State which region of the electromagnetic spectrum is used in each situation.

An optical fibre is inserted into a patient's body to examine the liver during a keyhole surgery.

Explain why visible light is more useful and safer than X-rays during this surgery.

Fig. 1.1 shows the optical fibre used. The arrow shows the initial direction of the ray of visible light. 

Fig. 1.1

Draw the path of visible light along the fibre from one end to the other.

A technician uses an optical fibre in a factory to view a pipe blockage. The blockage is round a bend, shown in Fig. 1.2.

The glass from which the optical fibre is made has a refractive index of 1.3.