Unit 15: Physical Optics — Mcqs

MCQ 15.1.When the light from two lamps falls on a screen, no interference pattern can be obtained. Why is this?

MCQ 15.2.Monochromatic light illuminates two narrow parallel slits. The interference pattern which results is observed on a screen some distance beyond the slits. Which change increases the separation between the dark lines of the interference pattern?

MCQ 15.3.Using monochromatic light, interference fringes are produced on a screen placed a distance L from a pair of slits of separation d. The separation of the fringes is y. Both d and L are now doubled. What is the new fringe separation?

MCQ 15.4.Which of the following is not a necessary condition for two waves to produce interference?

MCQ 15.5.The colours appeared on a soap bubble are due to which phenomenon of light?

MCQ 15.6.Continuous water waves are diffracted through a gap in a barrier in a ripple tank. Which change will cause the diffraction of the waves to increase?

MCQ 15.7.Which property of a light wave can be determined using a diffraction grating?

MCQ 15.8.The central maximum in a diffraction grating is called: