Physics Objective (Multiple Choice) General Knowledge & General Science Questions & Answers for SSC-CGL, UPPSC, NDA, CDS and all one day examinations of India.
11. What is the stress known as when there is a relative displacement between various layers of solid?
[A] Tangential
[B] Linear
[C] Lateral
[D] Longitudinal
Show Answer
Correct Answer: A [Tangential]
Notes:
When successive layers of solid move on each other i.e. when there is a relative displacement between various layers of solid, the stress produced is called as Tangential stress.
12. Which of the following is correct about Surface Tension?
[A] It is a scalar quantity
[B] It is a molecular phenomenon
[C] Its root cause is the electromagnetic forces
[D] All of the above
Show Answer
Correct Answer: D [All of the above]
Notes:
Properties of Surface Tension: 1. it is a scalar quantity 2. it is a molecular phenomenon 3. its root cause is the electromagnetic forces
13. Which of the following is NOT an example of capillary action?
[A] Rise of ink in the fine pores of blotting paper
[B] soaking of water by a towel
[C] Wood swells in rainy season due to rise of moisture
[D] None of the above
Show Answer
Correct Answer: D [None of the above]
Notes:
Examples of capillarity : (i) Ink rises in the fine pores of blotting paper leaving the paper dry. (ii) A towel soaks water. (iii) Oil rises in the long narrow spaces between the threads of a wick. (iv) Wood swells in rainy season due to rise of moisture from air in the pores.
14. Which of the following is the S.I. unit of density?
[A] m-2
[B] m-3
[C] kg m-2
[D] kg m-3
Show Answer
Correct Answer: D [ kg m-3 ]
Notes:
The SI unit of density is kg m-3. It is a positive scalar quantity. The Gaussian unit of density is the gram per cubic centimeter which is equivalent to a gram per milliliter [1 g/cm3 = 1 g/ml].
15. What is the density of water at 4°?
[A] 1.0
[B] 1.0 × 102 kg m–3
[C] 1.0 × 103 kg m–3
[D] 10 kg m–3
Show Answer
Correct Answer: C [ 1.0 × 103 kg m–3 ]
Notes:
The density of water at 4°C (277 K) is 1.0 × 103 kg m–3. The relative density of a substance is the ratio of its density to the density of water at 4° C.
16. What happens to the time period of a spring pendulum based clock kept on the earth when it is taken to moon?
[A] Time period reduces to half
[B] Time period becomes twice
[C] Time period becomes one-sixth
[D] No change
Show Answer
Correct Answer: D [No change]
Notes:
Time of a spring pendulum is independent of acceleration due to gravity. That is why a clock based on spring pendulum will keep proper time every where on a hill or moon or in a satellite and time period of a spring pendulum will not change inside a liquid if damping effects are neglected.
17. What do we call the distance of particle from the mean position at that instant in S.H.M?
[A] Distance
[B] Displacement
[C] Phase
[D] Angular frequency
Show Answer
Correct Answer: B [Displacement]
Notes:
The displacement of a particle executing S.H.M. at an instant is defined as the distance of particle from the mean position at that instant.
18. What is the difference of two close frequencies of superimposing waves known as?
[A] Transverse frequency
[B] Beat frequency
[C] Normal frequency
[D] Angular frequency
Show Answer
Correct Answer: B [Beat frequency]
Notes:
The difference of two close frequencies of superimposing waves known as Beat frequency. It is represented by vbeat and Its S.I unit is s-1.
19. What is the relation between Time period(T) and angular frequency(ω) of a wave?
[A] T = 2π/ω
[B] T = 2πω
[C] T = π/2ω
[D] T = ω
Show Answer
Correct Answer: A [T = 2π/ω]
Notes:
Period T of oscillation of a wave is defined as the time any element of the medium takes to move through one complete oscillation. It is related to the angular frequency ω through the relation T = 2π/ω.
20. Which of the following sounds is produced by earthquakes before the main shock waves?
[A] low-frequency infrasound
[B] high-frequency ultrasound
[C] sounds between 200 Hz and 400 Hz
[D] None of the above
Show Answer
Correct Answer: A [low-frequency infrasound]
Notes:
Earthquakes produce low-frequency infrasound before the main shock waves begin which possibly alert the animals. It is observed that some animals get disturbed before earthquakes.
These questions are part of GKToday's 40,000+ GK Questions Course in GKToday Android Application which provides more than 40K questions with explanations suitable for all Competitive Exams of India.