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