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