Question
Explain that in day to day life we can't get coherent sources using two sodium lamps.
✓
Answer
→As shown in fig. if we use two sodium lamps illuminating two pin holes, we will not observe any interference fringes.
→This is because of the fact that light wave emitted from ordinary source undergoes abrupt phase changes in times of the order of $10^{-10}$ seconds.
→Thus, the light waves coming out from two independent sources of light will not have any fixed phase relationship and would be incoherent.
→When this happens, their intensities on the screen will add up.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
Evaluate Rydberg constant by putting the values of the fundamental constants in its expression.
Figure shows an electrolyte of AgCl through which a current is passed. It is observed that 2.68g of silver is deposited in 10 minutes on the cathode. Find the heat developed in the $20\Omega$ resistor during this period. Atomic weight of silver is 107.9g/mole.
→Define wavefront of a travelling wave. Using Huygens principle, obtain the law of refraction at a plane interface when light passes from a denser to rarer medium.
A parallel plate capacitor of capacitance C is charged to a potential V. It is then connected to another uncharged capacitor having the same capacitance. Find out the ratio of the energy stored in the combined system to that stored initially in the single capacitor.
Explain mutual induction using Faraday's two coil experiment. Obtain expression
Explain physical meaning of electric field.
The mutual inductance between two coils is 2.5H. If the current in one coil is changed at the rate of 1A/s, what will be the emf induced in the other coil?
A beam of alpha particles and protons enters a uniform magnetic field with same speed. Calculate the ratio between their radii of circular path in magnetic field.
In the following diagrams indicate which of the diodes are forward biased and which are reverse biased.
Explain paramagnetism and paramagnetic substances.