Exploring the Cosmos - Class Test 2 - Mapping the Universe
1. Long Baseline Interferometry is a technique often used in radio astronomy to
remove the effect of Cerenkov radiation.
reduce the effect of light pollution in urban skies.
image neutrinos.
improve the resolution of objects.
2. Karl Jansky was the pioneer of
UV astronomy.
optical astronomy
infra-red astronomy.
radio astronomy.
3. The LIGO gravitational wave detectors
have arm lengths of 600 m.
have arm lengths of 4 km.
are bar detectors.
are currently under construction.
4. Cerenkov radiation is given off when
a particle is travelling slower than the speed of light in a medium
a particle is travelling faster than the speed of light in a medium
an electron is ionised from an atom
an electron recombines with an ionised atom
5. Why is the colour of the sun during sunset red?
The sun changes its colour in 24 h from blue to red and back to blue.
The diffraction of light is different. Blue light is more strongly diffracted.
The scattering of blue light is stronger than red light.
The refraction of light is different. Blue light is more strongly refracted.
6. Which of the following processes is responsible for the absorption of Infra-Red radiation?
Infra-Red radiation is not absorbed.
Excitation of vibrational modes of molecules.
Breaking of the chemical bonds.
Splitting of the atomic nuclei.
7. The ISO satellite is sensitive to
X-rays.
Gamma rays.
IR.
UV.
8. The objective of a telescope is
the part of it which first converges the light.
the object under observation.
the adaptor between the telescope and the human eye.
the reason why that telescope has been buil
9. As light passes from one medium to another, its direction of travel changes. What is the name of this effect?
Refraction
Diffraction
Interference
Dispersion
10. How does an infrared telescope make detections?
By detecting oscillating electric signals generated by incident photons.
By monitoring changes in temperature caused by incident photons.
By monitoring the number of electrons released by incident photons.
By directly detecting the number of incident photons.
11. Which of the following processes is responsible for absorption of infrared radiation by the atmosphere?
Conduction in an upper part of the atmosphere.
Interaction of the radiation with the nuclei of atoms in the atmosphere.
The breaking of chemical bonds in ozone.
The excitation of the vibrational modes of water vapour molecules.
12. The twinkling of the stars is due to
refraction.
scattering.
absorption.
diffusion.
13. A Charge Coupled Device is used in telescopes to
compensate for sagging of the mirror.
detect light.
improve light gathering.
reduce the effect of segmentation of mirrors.
14. The Spitzer satellite uses
a Schmidt-Cassegrain design
a Cassegrain design
a prime focus arrangement
a grazing incidence mirror
15. The ISO satellite is sensitive to
Gamma rays.
IR.
X-rays.
UV.
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