Question
Two sources of waves are called coherent if
✓
Answer
(c)Two coherent source must have a constant phase difference otherwise they can not produce interference.
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
Myopia is due to
A cylindrical block of density $\rho$ is partially immersed in a liquid of density $3\rho .$ The plane surface of the block remains parallel to the surface of the liquid. The height of the block is $60\, cm.$ The block performs $SHM$ when displaced from its mean position. [Use $ g = 9.8\, m/s^2$]
→A real gas within a closed chamber at $27^{\circ} \mathrm{C}$ undergoes the cyclic process as shown in figure. The gas obeys $P V^3=\mathrm{RT}$ equation for the path $A$ to $B$. The net work done in the complete cycle is (assuming $R=8 \mathrm{~J} / \mathrm{molK}$ ):
→In the circuit shown in the figure below, which of the following statement is incorrect ?
$Assertion :$ In free expansion of an ideal gas, the entropy increases.
$Reason :$ Entropy increases in all natural processes.
→$Reason :$ Entropy increases in all natural processes.
On a horizontal frictionless frozen lake, a girl $36 \,kg$ and a box $9 \,kg$ are connected to each other by means of a rope. Initially, they are $20 \,m$ apart. The girl exerts a horizontal force on the box, pulling it towards her. How far has the girl travelled when she meets the box?
→Two vessels of different materials are similar in size in every respect. The same quantity of ice filled in them gets melted in $20$ minutes and $30$ minutes. The ratio of their thermal conductivities will be
→A uniform beam of positively charged particles is moving with a constant velocity parallel to another beam of negatively charged particles moving with the same velocity in opposite direction separated by a distance $d.$ The variation of magnetic field $B$ along a perpendicular line draw between the two beams is best represented by
→A tuning fork of frequency $480 Hz$ produces $10$ beats per second when sounded with a vibrating sonometer string. What must have been the frequency of the string if a slight increase in tension produces lesser beats per second than before ..... $Hz$
→A solid metallic sphere of radius $r$ is allowed to fall freely through air. If the frictional resistance due to air is proportional to the cross-sectional area and to the square of the velocity, then the terminal velocity of the sphere is proportional to which of the following?
→