physics MCQs – Page 41

Practise multiple-choice questions from physics for competitive examinations and subject revision. Review each marked answer and report any item that may be outdated or unclear.

physics Mcqs
801. Which one of the following is not vector quantity _______?
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A. Speed

B. Acceleration

C. Displacement

D. Force

802. The minimum wavelength of X-rays produced by the bombardment of electrons on the screen of a television set where the accelerating potential is 2.0K V will be______________?
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A. 6.2 x 10-10m

B. 4 x 10-10m

C. 9.1 x 10-18m

D. 3.11 x 10-10m

803. An OP-AMP comparator is a circuit that compares the signal voltage on one of its inputs with a ______________?
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A. Output

B. Reference voltage on the other

C. Non-inverting voltage at output

D. Virtual input

804. The semiconductor diode can be used as a rectifier because _______________?
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A. It has high resistance to the current flow when reverse biased

B. Its conductivity increases with rise of temperature.

C. It has low resistance to the current flow when forward biased.

D. It has low resistance to the current flow when forward biased & high resistance when reverse biased.
805. The specially designed semi-conductor diodes used as fast counters in electronic circuits are______________?
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A. Solar cells.

B. Photo voltaic cell

C. Photo diodes

D. The light emitting diodes

806. The pressure exerted by a column of mercury 76cm high and at 0C is called_______________?
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A. 1 atmosphere

B. data is insufficient

C. 1 Newton per square meter

D. 1 Pascal

807. The core of a transformer is laminated to reduce energy losses due to__________?
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A. Eddy currents

B. Resistance in winding

C. Hysteresis

D. None of these

808. The value of resistivity for insulator is of the order of____________?
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A. 106 ohm metre

B. 107 ohm metre

C. 108 ohm metre

D. 105 ohm metre

809. The centripetal acceleration produced in a rotating body is commonly due to change on_________of body?
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A. direction

B. both

C. None of these

D. magnitude

810. In which process entropy remains constant________________?
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A. isothermal

B. adiabatic

C. isobaric

D. isochoric

811. Forward current through a semi conductor diode circuit is due to____________?
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A. holes

B. electron

C. majority carriers

D. minority carriers

812. Acceptor and donor impurities donate______________?
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A. p-carriers and n-carriers respectively

B. n-carriers only

C. p-carriers only

D. n-carriers and p-carriers respectively

813. Mirage is an example of ___________?
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A. Scattering of light

B. reflection of light

C. Refraction and total internal reflection of light

D. refraction of light

814. The purpose of flywheel in the engines is________________?
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A. to smooth out the energy variation

B. to add more weight to engine to work it stable

C. to start engine

D. both A and B

815. Tick the correct statement_________________?
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A. Moderators reflect the neutrons

B. Moderators bring the neutrons to rest

C. Moderators absorb the neutrons

D. Moderators slow down the neutrons
816. Electric current in a solid metal conductor is caused by the movement of what ?
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A. Electrons

B. Protons

C. Metal atoms

D. Metal ions

817. The unit of entropy is________________?
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A. Kgm2/sec2.K

B. J/K

C. J.K

D. N.m/sec

818. Metabolism is the name of a process in which energy transformation takes place within______________?
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A. Laboratory

B. Human body

C. Atmosphere

D. Heat engine

819. In normal state of energy the incident high energy photons will be______________?
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A. Cause X-ray emission

B. Absorbed

C. Stimulated

D. Cause laser production

820. The device used for conversion of D.C. to A.C. is called______________?
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A. A rectifier

B. Converter

C. Inverter

D. Oscillator