Question 14: NCERT Solutions for 12th Class Physics: Chapter 10-Wave Optics
Let us list some of the factors, which could possibly influence the speed of wave propagation:
(i) nature of the source.
(ii) direction of propagation.
(iii) motion of the sources and/or observer.
(iv) wavelength.
(v) intensity of the wave. On which of these factors, if any, does
(a) the speed of light in vacuum,
(b) the speed of light in a medium (say glass or water) depend?
Solution:
(a) Speed of light in vacuum is independent of all the factors listed above. It is also independent of relative motion between source and observer.
(b) Dependence of speed of light in a medium.
(i) The speed of light in a medium does not depend on the nature of the source. Although speed is determined by the properties of the medium of propagation.
(ii) The speed of light in a medium is independent of the direction of propagation for an isotropic media.
(iii) The speed of light is independent of the motion of the source relative to the medium but it depends upon the motion of the observer relative to the medium.
(iv) The speed of light in a medium depends on wavelength of light i.e., v ∝ λ..
(v) The speed of light in a medium is independent of intensity.
Check the complete chapter with solutions.
NCERT Solutions for 12th Class Physics: Chapter 10-Wave Optics