The device which produced highly coherent source is
A.Fresnel bi prism
B.laser
C.Young's double slit
D. Lloyd's mirror
B. laser
The correct answer is B. laser.
A laser (Light Amplification by Stimulated Emission of Radiation) is a device that produces a highly coherent source of light. The light produced by a laser is made up of waves that are all in phase with each other, meaning the peaks and troughs of the waves align perfectly. This coherence is what allows lasers to produce a concentrated beam of light that can be used in various applications, such as precision measurements, communication, and medical procedures.
On the other hand, options A, C, and D (Fresnel bi prism, Young's double slit, and Lloyd's mirror) are not designed to produce highly coherent light sources. While they may be used in optics experiments and have their own specific purposes, they do not provide the same level of coherency as a laser.