WorksheetsInterference unit
Total questions: 10
Worksheet time: 5mins
1. Interference of light is
(a). The modification in the distribution of light energy due to the superposition of two coherent waves.
(b). The redistribution of light energy due to the superposition of two coherent waves.
(c). The modification in the distribution of light energy due to the superposition of two incoherent waves.
(d). Both a and c
1. Which of the following is not the conditions for sustained interference
(a). The light waves superposing at a point may not have the same wavelength or same frequency.
(b). The amplitude of superposing light waves should be equal or almost equal.
(c). The waves superposing should either have the same phase or constant phase difference.
(d). Light sources must be very narrow and very close to each other.
1. Why the central ring is dark?
(a). Because the two interfering rays have a path difference (l) and the thickness is zero.
(b). Because the two interfering rays have a path difference (l/2) and the thickness is not zero.
(c). Because the two interfering rays have a path difference (l/2) and the thickness is zero.
(d). Because the two interfering rays have a path difference (l) and the thickness is not zero.
1. Why Newton’s
Rings are circular?
(a). Because the air film formed is wedge shaped and loci of points of equal thickness are circles concentric with point of contact.
(b). Because the air film formed is spherical shaped and loci of points of equal thickness are circles concentric with point of contact.
(c). Because the air film formed is wedge shaped and loci of points of variable thickness are circles nonconcentric with point of contact.
(d). Because the air film formed is wedge shaped and loci of points of equal thickness are circles nonconcentric with point of contact.
1. What is the function of the 45° inclined glass plate in wedge method experiment
(a). It turns the light rays coming from an extended source to ninety degrees and so the rays fall incline on the Plano-convex lens.
(b). It turns the light rays coming from an extended source to ninety degrees and so the rays fall normally on the Plano-convex lens.
(c). It turns the light rays coming from an extended source to ninety degrees and so the rays fall parallel on the Plano-convex lens.
(d). None of the above
1. If the glass plate is replaced with plane mirror in the Newton’s ring
(a). Interference formed
(b). Interference not formed
(c). Interference fringes compressed
(d). Interference fringes expands
1. If sodium light is replaced with white light?
(a). No change
(b). Interference will be observed with increase in fringe width
(c). Colored interference will be observed
(d). Colored interference will be observed with decrease in fringe width
1. Principle of physics involved in Newton’s rings and Wedge method experiments
(a). Interference of Reflected light waves
(b). Interference of Refracted light waves
(c). Interference of un polarized light waves
(d). None of the above
1. Monochromatic light means
(a). Single colour.
(b). Double Colour
(c). Single Wavelength
(d). Both a and c
1. Coherent source have the properties of
(a). Two waves have same frequency, same amplitude and are in out of phase with each other.
(b). Two waves have different frequencies, same amplitude and are in same phase with each other.
(c). Two waves have same frequency, same amplitude and are in same phase with each other.
(d). Two waves have different frequencies, different amplitudes and are in same phase with each other.
