Electromagnetic Spectrum

Which statement about electromagnetic waves is correct?

• All electromagnetic waves are harmful to people

• All electromagnetic waves have the same wavelength

• In Vacuum, all electromagnetic waves travels at the same speed

• In Vacuum, visible light travels faster than all the other electromagnetic waves

Which of the following regions of electromagnetic spectrum can be used to cook food?

• Infrared only

• Microwave only

• Infrared and Microwave only

• No region can be used

Which region of the electromagnetic spectrum is used to communicate with artificial satellites?

• Radio waves

• Microwaves

• Infrared

• Visible Light

A lamp is used to sterilize water in an aquarium, what light is used?

• Infrared

• Red light

• Green light

• Ultraviolet

Which statement about microwave is correct?

• Microwaves are not used to communicate with satellites because they are blocked by clouds

• The wavelengths of microwaves are shorter than visible light

• The frequencies of microwaves are lower than radio waves

Which statement about optical fibers is correct?

• Optical fibers carry microwave signals

• Optical fibers cannot be used to transmit television signals

• Only visible light is used in optical fibers because only visible light can undergo total internal reflection

• Visible light and infrared are used because glass is transparent to these waves

The electromagnetic spectrum is shown in the table below.

• Wavelength

• Speed

• Frequency

• Amplitude

Which list shows the parts of the electromagnetic spectrum in order of decreasing wavelength?

• Radio waves, ultraviolet, microwaves

• Microwaves, infrared, visible light

• Ultraviolet, visible light, infrared

Which of the following groups contains only electromagnetic waves?

• Radio waves, sound waves, microwaves

Which of the following sentences about infrared waves is trus?

• They can be used to treat cancerous tumors

• They can be used to make image of bones, through the skin

• They can be used for cooking

• They are used to send communication signals to satellites