Two waves of same frequency have amplitude in the ratio 2:1. Find the ratio of the maximum and the minimum amplitudes and intensities in the region of interference. 


Correct option is

3: 1, 9: 1


If a1 and a2 be the amplitudes of the waves then, in the interference pattern the maximum and the minimum resultant amplitudes will be (a1 + a2) and (a1 ~ a2) respectively. That is






What do you know about the speed of red and blue light (i) In vacuum, (ii) In glass? The refraction index of glass for blue light is 1.665 and for red light is 1.645. (The speed of light in vacuum is ).



(a) The wavelength of a given light is 0.00006 cm. Express this wavelength in micron and in angstrom. 

(b) What will be its wavelength in water, if the refractive index of water be 4/3.


The wavelength of a given light in vacuum is 6400 Ã…. Calculate its wavelength in water. Refractive index of water is 4/3.  


A light-ray of 6000 Ã… wavelength travelling in vacuum enters a medium of refractive index 1.5. Find the speed and the wavelength of the ray in the medium. 


The absolute refractive index of air is 1.0003 and the wavelength of yellow light in vacuum is 6000 Ã…. Find the thickness of air column which will have one more wavelength of the yellow light than in the same thickness of vacuum.


The number of waves in a 4-cm thick strip of glass is the same as in 5-cm water, when the same monochromatic light travels in them. If the refractive index of water be 4/3, what will be of glass?


What is the content of energy in X-ray photon of wavelength 10 Ã…? Given J-s,  


Calculate de-Broglie wavelength for an electron and a proton moving with the same speed of 105 m/s. (me = 9.1×10 –31 kg, mp = 1.67 × 10 –27 kg and h = 6.63 × 10 –34 Js).


The ratio of intensities of two waves is 25:16. What is the ratio of amplitudes? If these two waves produce interference, then find the ratio of maximum and minimum intensities.



Two coherent sources X and Y of light of wavelength

λ = 6.2 × 10 –5 cm, produce interference. If both the sources are in the same phase and P is an arbitrary observation point, then calculate XP – YPwhen the point P is (i) At the bright band of 10th order, (ii) At the dark band between third and fourth order maxima.