Charge q is uniformly spread on a thin ring of radius R. The ring rotates about its axis with a uniform frequency f Hz. The magnitude of magnetic induction at the centre of the ring […]
A short bar magnet of magnetic moment 0.4 JT⁻¹ is placed in a uniform magnetic field of 0.16 T. The magnet is in stable equlibrium when the potential energy is
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(a) -0.064 […]
A thin prism of angle 15⁰ made of glass of refractive index µ₁ = 1.5 is combined with another prism of glass of refractive index µ₂ = 1.75. The combination of the prism produces dispersion […]
A particle of masses m is thrown upwards from the surface of the earth, with a velocity u. The mass and the radius of the earth are, respectively, M and R. G is gravitational constant […]
The electric potential V at any point (x,y,z) all in meters in space is given by V = 4x² volt. The electric field at the point (1,0,2) in V/m is
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(a) 8 […]
Pure Si at 500 K has equal number of electron (nₑ) and hole (nₕ) concentrations of 1.5 x 10¹⁶ m⁻³. Doping by indium increases nₕ to 4.5 x 10²² m⁻³. The doped semiconductor is of […]
The threshold frequency for a photosensitive metal is 3.3 x 10¹⁴ Hz. If light of frequency 8.2 x 10¹⁴ Hz incident on this metal, the cut-off voltage for the photoelectric emission is nearly
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A thermocouple of negligible resistance produces an e.m.f. of 40 µV/⁰C in the linear range of temperature. A galvanometer of resistance 10 ohm whose sensitivity is 1 µA/div, is employed with the thermocouple. The smallest […]
An electron in the hydrogen atom jumps from excited state n to the ground state. The wavelength so emitted illuminates a photosensitive material having work function 2.75 eV. If the stopping potential of the photoelectron […]
A coil has resistance 30 ohm and inductive reactance 20 ohm at 50 Hz frequency. If an ac source, of 200 volt, 100 Hz, is connected across the coil, the current in the coil will […]
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