CSS General Science MCQs – Page 3 – Quiz

The speed of sound in dry air at 20 °C is about:

(A) 130 m/s
(B) 230 m/s
(C) 330 m/s
(D) None of these

Q. In an exceptionally stiff material such as diamond, the speed of sound is:
(A) 12,000 m/s
(B) 10,000 m/s
(C) 8,000 m/s
(D) 6,000 m/s

Q. The ratio of the speed of an object to the speed of sound in the fluid is called object’s:
(A) Travelling speed
(B) Mach Number
(C) Effects on speed
(D) None of these

Answers:
1. (D) None of these (343 m/s)
2. (A) 12,000 m/s
3. (B) Mach Number

When sound is reflected from floor, ceiling or a wall, it mixes with the original sound and changes its complexion, it is called as:

(A) Sound
(B) Echo
(C) Reverberation
(D) Noise

Q. The process of reducing the level of reverberation in a sound or signal is:
(A) Dereverberation
(B) Antireverberation
(C) Unreverberation
(D) None of these

Q. A reflection of sound that arrives at the listeners with a delay after the direct sound is called:
(A) Noise
(B) Echo
(C) Reverberation
(D) None of these

Answers:
1. (C) Reverberation
2. (A) Dereverberation
3. (B) Echo

The magnet always points in the same direction, if allowed to move freely i.e. towards North and South poles, because of:

(A) Gravitational field
(B) A lot of metal deposits on North and South Poles
(C) Due to attraction of North Pole and repulsion of Western Pole
(D) Earth is a huge magnet

Q. Materials that can be magnetized which are also the ones that are strongly attracted to a magnet are called:
(A) Ferromagnetic
(B) Magnetized
(C) Electromagnetic
(D) None of these

Q. A vector that characterizes the magnet’s overall magnetic properties is called:
(A) Magnetic field
(B) Magnetic Moment
(C) Polarity
(D) None of these

Answers:
1. (D) Earth is a huge magnet
2. (A) Ferromagnetic
3. (B) Magnetic Moment

The unit of home electricity energy consumption is:

(A) Watt hour
(B) Kilowatt hour
(C) Joule hour
(D) Kilojoule hour

Q. The Kilowatt hour is a unit of energy equal to ______ megajoules.
(A) 3.6
(B) 4.6
(C) 5.6
(D) 6.6

Q. The derived unit of energy within the International System of Units (SI) is:
(A) watt
(B) joule
(C) kilojoule
(D) None of these

Answers:
1. (B) Kilowatt hour
2. (A) 3.6
3. (B) joule

An electric current can produce:

(A) Chemical effect
(B) Magnetic effect
(C) Heating effect
(D) All of these three

Q. The SI unit of electric current is:
(A) Coulomb
(B) Ampere
(C) Joule
(D) None of these

Q. The SI unit of electric charge is:
(A) Coulomb
(B) Ampere
(C) Joule
(D) None of these

Answers:
1. (D) All of these three
2. (B) Ampere
3. (A) Coulomb