The Nature of Light Grade 9

The circumference of Earth is 40100 km. How many times can light travel around Earth in 1s?

• about 5 times

• about 7 times

• about 9 times

• about 10 times

The transfer of energy as electromagnetic waves called

• transmission

• radiation

• convection

• conduction

The light from stars in the sky may take years to reach Earth. In fact, it is possible that some of the stars we see now no longer exist.

• True

• False

The distance from the sun to Venus is 108,000,000 km. Calculate the time it takes for light to travel that distance.

• 6 min

• 60 sec

• 6 sec

• 360 min

How is the speed of a wave determined?

• by its frequency only

• by multiplying the wavelength and amplitude of the wave

• by multiplying the wavelength and frequency of the wave

• by multiplying the wavelength and the time taken

The entire range of EM waves is called the

• electromagnetic radiation

• electromagnetic regions

• electromagnetic colors

• electromagnetic spectrum

Changing amplitude or frequency is called

• conversion

• modulation

• interference

• Radar

Which EM waves can carry television signals?

• Radio waves

• Microwaves

• Visible light

• Ultraviolet light

Signals sent between Earth and artificial satellites in space are carried by

• radio waves

• microwaves

• infrared waves

• x-rays

our body can make vitamin D if

• we eat milk and fish.

• the skin is exposed to ultraviolet light in sunlight for certain periods of time.

• the skin is exposed to infrared waves in sunlight for certain periods of time.

• we use sunscreen with a high SPF.