Question
What is the coherent source?

Answer

Those two sources which emit waves of same frequency or same wavelength and the phase difference between them remains constant with time, are called coherent source.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

In $1959$ Lyttleton and Bondi suggested that the expansion of the Universe could be explained if matter carried a net charge. Suppose that the Universe is made up of hydrogen atoms with a number density $N,$ which is maintained a constant. Let the charge on the proton be: $e_p = -(1 + y)e$ where e is the electronic charge.
Show that the velocity of expansion is proportional to the distance from the centre.
In a cylindrical conductor, a direct current is flowing. Is there any electric field inside the conductor?
In order to have a current in a long wire, it should be connected to a battery or some such device. Can we obtain the magnetic due to a straight, long wire by using Ampere's law without mentioning this other part of the circuit?
Identify the electromagnetic waves whose wavelengths vary as
  1. $10^{–12 m} < \lambda < 10^{–8} m$
  2. $10^{–3 m} < \lambda< 10^{–1} m$
Write one use for each.
In the decay $^{64}Cu \rightarrow ^{64}Ni + e^+ + v,$ the maximum kinetic energy carried by the positron is found to be $0.650\ MeV.$
  1. What is the energy of the neutrino which was emitted together with a positron of kinetic energy $0.150\ MeV?$
  2. What is the momentum of this neutrino in $kg-m/s?$
Use the formula applicable to a photon.
A point source is placed at a depth h below the surface of water (refractive index = μ).
  1. Show that light escapes through a circular area on the water surface with its centre directly above the point source.
  2. Find the angle subtended by a radius of the area on the source.
A 1cm object is placed perpendicular to the principal axis of a convex mirror of focal length 7.5cm. Find its distance from the mirror if the image formed is 0.6cm in size.
Assume that the magnetic field is uniform in a cubical region and is zero outside. Can you project a charged particle from outside into the field so that the particle describes a complete circle in the field?
Describe the two shortcomings of Bohr model of atom.
A long narrow horizontal slit is placed $1\ mm$ above a horizontal plane mirror. The interference between the light coming directly from the slit and that after reflection is seen on a screen $1.0m$ away from the slit. Find the fringe$-$width if the light used has a wavelength of $700\ nm.$