Cosmology MCQs : This section focuses on the "Basics" of Cosmology. These Multiple Choice Questions (MCQs) should be practiced to improve the Cosmology skills required for various interviews (campus interview, walk-in interview, company interview), placement, entrance exam and other competitive examinations.
_________ is the science and study of the origin, current state and the future of the Universe.
Explanation: Cosmology is the science and study of the origin, current state and the future of the Universe.
Hubble was the only person observing galaxies outside the Milky Way.
C. Can be true or false
D. Can not say
Explanation: Hubble was not the only person observing galaxies outside the Milky Way, Humason helped him. They set out on measuring the spectra of nearby galaxies.
Hubble and Humason listed down _______ in their paper.
A. 20 Galaxies
B. 21 Galaxies
C. 22 Galaxies
D. 23 Galaxies
Explanation: Hubble and Humason listed down 22 Galaxies in their paper. Nearly all these galaxies exhibited redshift. They plotted the velocity (km/s) vs distance (Mpc).
The ___________ gives us a realistic estimate of the age of the universe.
A. Hubble constant
B. Humason constant
C. Cepheid constant
D. None of the above
Explanation: The Hubble constant gives us a realistic estimate of the age of the universe. The Ho would give the age of the universe provided the galaxies have been moving with the same velocity. The inverse of Ho gives us Hubble time.
Our universe is ∼_____ years old.
A. 14 million
B. 4 million
C. 4 billion
D. 14 billion
Explanation: Our universe is ∼14 billion years old.
Current value of Ho is ____ kms/sec/Mpc.
Explanation: Current value of Ho is 69 kms/sec/Mpc.
In _______, Edwin Hubble detected Cepheid’s in the Andromeda Nebula and estimated their distance.
Explanation: In 1924, Edwin Hubble detected Cepheid’s in the Andromeda Nebula and estimated their distance.
How many broad classes of these pulsating variable stars?
Explanation: There are 3 broad classes of these pulsating variable stars : Type-I Cepheids (or Classical Cepheids), Type-II Cepheids (or W Virginis Stars) and RR Lyrae Stars
Everything is moving away from us.
C. Can be yes or no
D. Can not say
Explanation: Yes,Everything is moving away from us. The galaxies are not stationary, there is some expansion harmonic always.
The units of the Hubble parameter are?
A. km sec Mpc−1
B. km sec -1 Mpc−1
C. km sec−1Mpc
D. km sec Mpc
Explanation: The units of the Hubble parameter are km sec−1Mpc−1. If one goes out a distance of – 1 Mpc, galaxies would be moving at the rate of 200 kms/sec. The Hubble parameter gives us the rate of expansion. As per Hubble and Humason, the value of Ho is 200 kms/sec/Mpc.