The phenomenon utilised in an optical fibre is
|
(a) Refraction |
(b) Interference |
|
(c) Polarization |
(d) Total internal reflection |
The phenomenon utilised in an optical fibre is
|
(a) Refraction |
(b) Interference |
|
(c) Polarization |
(d) Total internal reflection |
(d) Total internal reflection
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A charge +Q is moving upwards vertically. It enters a magnetic field directed to the north. The force on the charge will be towards
|
(a) North |
(b) South |
(c) East |
(d) West |
The frequency of the incident light falling on a photosensitive metal plate is doubled, the kinetic energy of the emitted photoelectrons is
|
(a) Double the earlier value |
(b) Unchanged |
|
(c) More than doubled |
(d) Less than doubled |
Electrons with energy 80 keV are incident on the tungsten target of an X-ray tube. K shell electrons of tungsten have ionization energy 72.5 keV. X-rays emitted by the tube contain only
|
(a) A continuous X-ray spectrum (Bremsstrahlung) with a minimum wavelength of ~ 0.155Å |
|
(b) A continuous X-ray spectrum (Bremsstrahlung] with all wavelengths |
|
(c) The characteristic X-rays spectrum of tungsten |
|
(d) A continuous X-ray spectrum (Bremsstrahlung) with a minimum wavelength of ~ 0.155Å and the characteristic X-ray spectrum of tungsten |
What will be the resultant magnetic field at origin due to four infinite length wires. If each wire produces magnetic field 'B' at origin
|
(a) 4 B |
(b) |
(c) 2 |
(d) Zero |