Exploring the Cosmos - Class Test 1 - Mapping the Universe
1. Which of the following statements correctly describes the wavelength of an electromagnetic wave?
The wavelength is the distance between a trough and a peak.
The wavelength is the distance travelled by the wave in a short time.
The wavelength is the distance between two consecutive peaks.
The wavelength is the distance travelled by the wave in 1 second.
2. Why does a light ray bend when it crosses the boundary between two different media at an oblique angle?
Because the speed of light changes.
Because the frequency increases.
Because it interferes with the surface.
Because the amplitude is reduced.
3. A Newtonian telescope has
a diverging secondary mirror
just the primary mirror
a flat secondary mirror
a correction plate
4. As light passes from one medium to another, its direction of travel changes. What is the name of this effect?
Refraction
Interference
Diffraction
Dispersion
5. Diffraction gratings are used to
reduce diffraction of telescopes.
increase the resolution of telescopes.
detect infrared radiation.
break up light into a spectrum.
6. The speed of light in glass is
reduced by approximately 1%
increased by approximately 50%
the same as in vacuum
reduced by approximately 60%
7. Diffraction gratings are used for
increasing the angular resolution of telescopes.
reducing the diffraction of telescopes.
detecting microwave radiation.
analysing the light spectrum.
8. Which of the following parameters is the same for all electromagnetic waves propagating in a vacuum?
Wavelength
Speed
Colour
Amplitude
9. Which of the following parameters is the same for all electromagnetic waves propagating in a vacuum?
Amplitude
Colour
Speed
Wavelength
10. Why does a light ray bend when it crosses the boundary between two different media at an oblique angle?
Because it interferes with the surface.
Because the amplitude is reduced.
Because the frequency increases.
Because the speed of light changes.
11. A Newtonian telescope has
a correction plate.
just the primary mirror.
a diverging secondary mirror.
a flat secondary mirror.
12. The Hubble telescope was placed in space in order
to not be limited by the Earth’s atmosphere.
to be close to the stars.
to not be limited by the Earth’s horizon.
to improve the magnification.
13. An electromagnetic wave with a wavelength of 600 nm is
ultraviolet radiation.
infrared radiation.
visible radiation.
microwave radiation.
14. Which of the following uses a grazing incidence telescope?
Chandra X-ray satellite.
International Space Observatory.
International Ultraviolet Explorer.
International Space Station.
15. The angle through which a ray of light is bent by a glass prism depends on the
reflectivity of the prism.
photoelectric effect.
brightness of the light.
wavelength of the light.
16. The focal length of an ideal mirror depends on
wavelength of the light.
brightness of the light.
photoelectric effect.
reflectivity of the prism.
17. Light can be described as having a “dual†nature. What does this mean?
Light behaves like a wave and like a particle.
If light moves in one direction, then it moves in the opposite direction also.
Light can be expressed as brightness and colour.
Light goes slow and fast.
18. What is the angular size of the Moon?
0.5 arcseconds
0.5 arcminutes
5 degrees
0.5 degrees
19. Which of the following space-based telescopes detected water in the Orion nebula?
The International Space Observatory (ISO)
Chandra
The International Ultraviolet Explorer (IUE)
Hubble
20. If the width of the objective of a telescope is doubled, what happens to its light gathering power?
The light gathering power increased by a factor of four.
The light gathering power is decreased by a factor of four.
The light gathering power remains the same.
The light gathering power is increased by a factor of two.
21. For a telescope the objective focal length is 80 cm and the eyepiece focal length is 2 cm, what is the magnification?
160
78
40
less than 1
22. To detect dim objects a telescope needs
high resolution.
a long tube.
large diameter.
high magnification.
23. A Charge Coupled Device is used in telescopes to
improve light gathering.
reduce the effect of segmentation of mirrors.
detect light.
compensate for sagging of the mirror.
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