Electromagnetic Waves Quiz

Who predicted the existence of radio waves in 1865?

• Heinrich Hertz

• James Clerk Maxwell

• Albert Einstein

• Nikola Tesla

What is the range of wavelengths used by humans for radio wave communication?

• Between 1m and 100m

• Between 10m and 100km

• Between 1m and 100km

• Between 10m and 100m

What does VLF stand for?

• Very Low Frequency

• Variable Low Frequency

• Very Long Frequency

• Variable Long Frequency

For what purpose are radio waves with long wavelengths useful in communication?

• They can penetrate water to a significant depth.

• They are used for digital broadcasting only.

• They can only travel in a straight line.

• They are used exclusively for satellite communication.

What is the application of radio waves in the field of medicine?

• X-ray imaging

• Ultrasound imaging

• Magnetic resonance imaging (MRI)

• CT scans

How do radio waves enable communication over hills and valleys?

• By diffraction

• By direct line of sight

• By reflection from the moon

• By transmission through the ground

What is decoded into TV pictures or audio by an aerial?

• Light waves

• Sound waves

• Radio waves

• Microwaves

What is the wavelength range of microwaves?

• Between around 1mm and 1m

• Between around 1cm and 10m

• Between around 10mm and 100m

• Between around 1μm and 1mm

Why are microwaves less effective at heating food that contains no water?

• Because microwaves cannot penetrate dry food

• Because microwaves heat up water molecules inside food

• Because microwaves are reflected by dry food

• Because microwaves are absorbed by the container instead

What has led to the increase in the use of microwaves for mobile phones?

• The need to heat food remotely

• The need to communicate with base stations

• The need to generate electricity

• The need to cook food faster