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