General Science - Physics MCQs
Physics Objective (Multiple Choice) General Knowledge & General Science Questions & Answers for SSC-CGL, UPPSC, NDA, CDS and all one day examinations of India. These questions are part of GKToday’s 35000+ MCQs Bank Course in GKToday Android App
31. 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.
32. What is the wavelength range of Radio waves?
[A] between 400 nm and 800 nm
[B] between 1 nm and 10-3 nm
[C] more than 0.1 m
[D] None of the above
Show Answer
Correct Answer: C [more than 0.1 m]
Notes:
Radio waves are produced by the accelerated motion of charges in conducting wires. They are used in radio and television communication systems. They have frequencies from 300 GHz to as low as 3 kHz, and having wavelength range more than 0.1 m.
33. Which of the following is NOT a mechanical wave?
[A] Sound wave
[B] Seismic wave
[C] Light wave
[D] Water waves
Show Answer
Correct Answer: C [Light wave]
Notes:
Sound wave, seismic wave and water waves are mechanical waves whereas light wave is an electromagnetic wave.
34. What is the speed of sound in air at 0 ºC?
[A] 3 x 108 m/s
[B] 344 m/s
[C] 441m/s
[D] 331 m/s
Show Answer
Correct Answer: D [331 m/s]
Notes:
The speed of sound in air is 331 m/s at 0 ºC and 344 m/s at 22 ºC.
35. Which of the following can be measured using SONAR?
[A] distance of underwater objects
[B] direction of underwater objects
[C] speed of underwater objects
[D] All of the above
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Correct Answer: D [All of the above]
Notes:
The acronym SONAR stands for Sound Navigation And Ranging. Sonar is a device that uses ultrasonic waves to measure the distance, direction and speed of underwater objects.
36. What do we call the mode of transmission of heat by which heat travels from one part of a body to another by the actual motion of the heated particles of the body?
[A] Conduction
[B] Convection
[C] Radiation
[D] None of the above
Show Answer
Correct Answer: B [Convection]
Notes:
Convection is that mode of transmission of heat by which heat travels from one part of a body to another by the actual motion of the heated particles of the body.
37. What is the absorptive power of a perfectly black body?
[A] 0
[B] 1
[C] 100
[D] -100
Show Answer
Correct Answer: B [1]
Notes:
The absorptive power of a perfectly black body is maximum and its value is unity.
38. Which of the following is true about a cyclic process?
[A] the total heat absorbed equals the work done by the system.
[B] the system returns to its initial state
[C] Both a and b
[D] None
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Correct Answer: C [Both a and b]
Notes:
In a cyclic process, the system returns to its initial state and the total heat absorbed equals the work done by the system.
39. Which of the following statements state that no process is possible whose sole result is the transfer of heat from a colder object to a hotter object?
[A] Kevin-Plank statement
[B] Einstein’s statement
[C] Clausius statement
[D] None of the above
Show Answer
Correct Answer: C [Clausius statement]
Notes:
Clausius statement: No process is possible whose sole result is the transfer of heat from a colder object to a hotter object.
40. What is the refractive index of water?
[A] 1
[B] 1.01
[C] 1.33
[D] 1.78
Show Answer
Correct Answer: C [1.33]
Notes:
The refractive index of air is 1.33.
