13 Electromagnetic Spectrum 2019 J & 2020 J/N

An eclipse of the Sun happens when the Moon comes between the Earth and the Sun.

Which statement is correct?

• Infra-red radiation from the Sun disappears before visible light and ultra-violet radiation.

• Ultra-violet radiation from the Sun disappears before visible light and infra-red radiation.

• Visible light from the Sun disappears before ultra-violet radiation and infra-red radiation.

• Infra-red radiation, ultra-violet radiation and visible light from the Sun all disappear at the same moment.

Which statement about microwaves is correct?

• Microwaves are longitudinal waves.

• The frequencies of microwaves are greater than the frequencies of visible light.

• The speed of microwaves in a vacuum is equal to the speed of visible light in a vacuum.

• The wavelengths of microwaves are smaller than the wavelengths of infra-red.

What is the speed of X-rays in a vacuum and in air?

• in a vacuum: 3.0 × 10^6 m/s, in air: 3.0 × 10^6 m/s

The diagram shows the electromagnetic spectrum. A word is missing from the label below the spectrum. Which word is missing?

• amplitude

• frequency

• speed

• wavelength

The wavelength of blue light changes from 4.7 × 10⁻⁷ m to 3.5 × 10⁻⁷ m as it passes from air to water. What is the speed of this light in water?

• 7.4 × 10⁷ m/s

• 1.3 × 10⁸ m/s

• 2.2 × 10⁸ m/s

• 3.0 × 10⁸ m/s

An intruder alarm sensor detects that a person is warmer than his surroundings. Which type of electromagnetic wave does the sensor detect?

• infrared

• radio

• ultraviolet

• visible light

The frequency of the microwaves used in a microwave oven is 2400 MHz. What is the wavelength of these microwaves?

• 0.125 m

• 8.00 m

• 125 m

• 7200 m

The diagram shows the electromagnetic spectrum.

Which types of wave are E, F and G?

Which type of radiation does a remote controller use to send its instructions to a TV set?

• γ-rays

• infrared radiation

• ultraviolet radiation

• X-rays

The diagram shows three types of electromagnetic radiation listed in a particular order. The electromagnetic radiation is travelling in a vacuum.

Which quantities increase in magnitude going from left to right across the list?

• frequency only

• neither speed nor frequency

• speed and frequency

• speed only