13 Electromagnetic Spectrum 2022 N

The diagram shows the electromagnetic spectrum. The numbers indicate the approximate wavelength at the boundaries between the various regions of the spectrum.

For a device to be able to make use of electromagnetic radiation, it needs an aerial of approximately the same size as the wavelength of the radiation it is designed to work with.

Which statement is correct?

• A mobile phone uses radiation from region P.

• A television satellite dish uses radiation from region Q.

• The receptor cells in an eye use radiation from region R.

• The remote controller for a television uses radiation from region U.

Microwaves and X-rays are regions of the electromagnetic spectrum. Which statement about microwaves and X-rays is correct?

• Microwaves and X-rays have the same frequency.

• Microwaves and X-rays travel at the same speed in a vacuum.

• Microwaves have a shorter wavelength than X-rays.

• Microwaves travel at a lower speed than X-rays in a vacuum.

Visible light has a frequency of approximately 5.0 x 10¹⁴ Hz.

M and N are two other types of electromagnetic radiation.

The frequency of M is 5.0 x 10⁶ Hz.

The frequency of N is 5.0 x 10¹⁵ Hz.

Which types of radiation are M and N?

• M: radio waves,

  N: infrared

• M: radio waves,

  N: ultraviolet

• M: ultraviolet,

  N: X-rays

• M: X-rays,

  N: infrared

Two students are describing different types of electromagnetic radiation. student 1: This radiation is used in communications. student 2: This radiation is used in remote controllers. Which row shows the possible type of radiation that each student is describing?

Which wave is not an electromagnetic wave?

• microwaves

• radio

• sound

• ultraviolet

What is the speed of microwaves in air?

• 3 × 10⁸ μm/s