A metal conductor of length 1m rotates vertically about one of its ends at angular velocity 5 radian per second. If the horizontal component of earth’s magnetic field is 0.2×10⁻⁴ T, then the e.m.f. developed […]
A coil of resistance and 1.0 H inductance is connected to an a.c. source of frequency 200/2π Hz. Phase angle between potential and current will be
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(a) 0⁰ (b) 30⁰ (c) 90⁰ […]
If the minimum energy of photons needed to produce photoelectrons is 3 eV, bombardinbg the photoelectric material by a number of photons of 2.5 eV also one can get
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(a) Photoelectrons of […]
A particle of mass 1 mg has the same wavelength as an electron moving with a velocity of 3 x 10⁶ ms⁻¹. The velocity of the particle is
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(a) 3 x 10⁻³¹ […]
Calcium plate has a maximum possible radiation wavelength 400 nm to eject electrons. Its work function is
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(a) 23 eV (b) 3.1 eV (c) 4.5 eV (d) None of these
Correct Answer: […]
A galvanometer acting as a voltmeter will have
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(a) A high resistance in parallel with its coil (b) A high resistance in series with its coil (c) A low resistance in parallel […]
A battery having e.m.f. 4 volt and internal resistance 0.5 Ω is connected with a resistance of 4.5 Ω, then the voltage at the terminal of battery is
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(a) 4.5 V (b) […]
The mass number of nucleus is always
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(a) Equal to atomic number (b) Less than atomic number (c) More than atomic number (d) Either (a) or ( c)
Correct Answer:
Either (Equal […]
A heavy nucleus at rest breaks into two fragments which fly off with velocities in the ratio 8:1. The ratio of radii of the fragments is
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(a) (1:2) (b) (1:4) (c) (4:1) […]
A choke is preferred to a resistance for limiting current in AC circuit because
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(a) Choke is cheap (b) There is no wastage of power (c) Choke is compact in size (d) […]
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