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