General Science – Physics MCQs
Physics Objective (Multiple Choice) General Knowledge & General Science Questions & Answers for SSC-CGL, UPPSC, UPSC, NDA, CDS and UPSC Civil Services Prelims Examinations.
51. What is the distance between the focus and the pole of the mirror is known as?
[A] Centre of Curvature
[B] Focal length
[C] Mirror number
[D] Radius of curvature
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Correct Answer: B [Focal length]
Notes:
The distance between the focus F and the pole P of the mirror is called the focal length of the mirror.
52. What is the total charge of the electric dipole?
[A] 0
[B] -1
[C] +1
[D] None of the above
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Correct Answer: A [0 ]
Notes:
The total charge of the electric dipole is zero.
53. What is the equivalent EMF of a series combination of n cells?
[A] the arithmetic mean of their EMFs
[B] the product of their individual EMF
[C] the sum of their individual EMF
[D] None of the above
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Correct Answer: C [the sum of their individual EMF]
Notes:
The equivalent emf of a series combination of n cells is just the sum of their individual EMFs.
54. Which of these are electrochemical cells?
[A] Galvanic cells
[B] Electrolytic cells
[C] Both a and b
[D] None of the above
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Correct Answer: C [Both a and b]
Notes:
There are two types of electrochemical cells: 1. A Galvanic Cell or Voltaic Cell 2. An Electrolytic cell
55. What do we call an arrangement of two unlike poles of equal strength separated by a small distance?
[A] Magnetic dipole
[B] Solenoid
[C] Toroid
[D] Electric dipole
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Correct Answer: A [Magnetic dipole]
Notes:
Magnetic dipole is an arrangement of two unlike magnetic poles of equal pole strength separated by a very small distance.
56. What is the source of energy in nuclear reactors which produce electricity?
[A] Nuclear Fission
[B] Nuclear Fusion
[C] Gamma decay
[D] None of the above
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Correct Answer: A [Nuclear Fission]
Notes:
Nuclear Fission is the source of energy in nuclear reactors which produce electricity.
57. What do we call the energy which should be supplied to the nucleus to break it up into its constituent particles?
[A] Excitation energy
[B] Binding energy
[C] Ionisation energy
[D] None of the above
Show Answer
Correct Answer: B [Binding energy]
Notes:
Binding energy is the energy which should be supplied to the nucleus in order to break it up into its constituent particles.
58. Which of the following material is commonly used to make control rods in a nuclear reactor?
[A] Indium
[B] Boron
[C] Cadmium
[D] All of the above
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Correct Answer: D [All of the above]
Notes:
Control rods are made of boron, silver, indium and cadmium that are capable of absorbing many neutrons without themselves fissioning.
59. How does a semiconductor behave at absolute zero temperature?
[A] like an insulator
[B] like a conductor
[C] depends on the material
[D] None of the above
Show Answer
Correct Answer: A [like an insulator]
Notes:
At or close to absolute zero a semiconductor behaves like an insulator. When an electron gains enough energy to participate in conduction (is “free”), it is at a high energy state. When the electron is bound, and thus cannot participate in conduction, the electron is at a low energy state.
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