Electromagnetic Spectrum (Cambridge (CIE) IGCSE Physics)

Fig. 7.1 shows the electromagnetic spectrum. One type of radiation is not labelled.

(i) On Fig. 7.1, add the label for the missing type of radiation.

[1]

(ii) The arrow in Fig. 7.1 indicates a property that is increasing.

  State the name of the property that is increasing in the direction of the arrow.

[1]

(iii) Compare the speeds of radio waves and visible light in a vacuum.

[1]

(i) Describe how X-rays are used for security in airports.

[2]

(ii) Explain the properties of X-rays that make them useful in airport security.

[2]

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

(i) In Fig. 7.1, section A and section B of the electromagnetic spectrum are not labelled.

State the names of parts A and B.

[2]

(ii) An electromagnetic wave has a wavelength of 1.0 × 10^–9 m. Use Fig. 7.1 to identify the type of electromagnetic wave.

[1]

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.

(i) Remote controllers for televisions

[1]

(ii) Killing bacterial cells

[1]

Fig. 7.1 shows some parts of the electromagnetic spectrum.

(i) In Fig. 7.1, one part of the electromagnetic spectrum is not labelled.

State the name of this part.

[1]

(ii) The speed of visible light waves in a vacuum is 3.0 × 10⁸ m / s.

Suggest a value for the speed of infra-red waves in a vacuum.

speed = .................................................. m / s

[1]

(iii) Some parts of the electromagnetic spectrum have a wavelength shorter than that of visible light. State one example.

[1]

(i) X-rays and γ-rays are used in hospitals.

Describe one medical use for X-rays and one use for γ-rays.

[1]

(ii) Explain why γ-rays are dangerous to living things.

[1]

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

(i) Complete the labels on Fig. 7.1.

[2]

(ii) State two properties that are the same for all waves in the electromagnetic spectrum.

[2]

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

(i) Detecting objects without opening baggage at a security check

[1]

(ii) Television remote control

[1]

(iii) Satellite television transmissions

[1]

Extended tier only

Optical fibres are used for high speed broadband.

Short wavelength visible light and infrared radiation are used to achieve this fast broadband. Explain why.

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.

Extended

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.

Extended

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.

(i) Calculate the critical angle of the glass.

[3]

(ii) The light does not reach the blockage. Suggest why.

[3]

Fig.9.1 represents the seven main regions of the electromagnetic spectrum.

(i) In Fig.9.1, one region is not named.

  State the name of the radiation in this region.

[1]

(ii) State which region has waves with the longest wavelength.

[1]

Tick the box for the wave with the lowest speed in air.

ultraviolet

ultrasound

visible light

A group of students want to determine the speed of sound in air.

Describe a method they can use. State the measurements they need to make.

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.

Extended tier only

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.

frequency = .................................... 

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.

(i) State the wavelength of the radio wave in Fig 1.1.

[1]

(ii) Sketch on Fig. 1.1 a wave that has a greater amplitude and lower frequency.

[2]

Extended tier only

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

Calculate the wavelength of this radio wave.

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

Extended tier only 

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

(i) Complete Table 1.1 by filling in the missing EM waves.

[3]

(ii) Suggest what the arrow is indicating.

[1]

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

Fig. 1.1

Describe the interaction between the x-rays and 

(i) soft tissue.

[1]

(ii) bone.

[1]