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Direction : Questions number 1 – 3 are based on the following paragraph. An initially parallel cylindrical beam travels in a medium of refractive index µ(I) = µ 0 + µ 2I, where µ0 and µ2 are positive constants and I is the intensity of the light beam. The intensity of the beam is decreasing with increasing radius. 1. The initial shape of the wavefront of the beam is :(1) planar (2) convex (3) concave (4) convex near the axis and concave near the periphery Ans. (1) 2. The speed of the light in the medium is :(1) maximum on the axis of the beam (2) minimum on the axis of the beam (3) the same everywhere in the beam (4) directly proportional to the intensity I Ans. (2) 3. As the beam enters the medium, it will :(1) travel as a cylindrical beam (2) diverge (3) converge (4) diverge near the axis and converge near the periphery Ans. (3) Directions : Questions number 4 – 5 are based on the following paragraph. A nucleus of mass M + Dm is at rest and decays The binding energy per nucleon for the parent nucleus is E1 an that for the daughter nuclei is E2. Then :(1) E1 = 2E2 (2) E2 = 2E1 (3) E1 > E2 (4) E2 > E1 Ans. (4) Directions : Questions number 6 – 7 contain Statement-1 and Statement-2. Of the four choices given after the statements, choose the one that best discribes the two statements. 6. Statement-1 : When ultraviolet light is incident on a photocell, its stopping potential is V0 and the maximum kinetic energy of the photoelectrons is K max. When the ultraviolet light is replaced by X-rays, both V0 and Kmax increase. Statement-2 : Photoelectrons are emitted with speeds ranging from zero to a maximum value because of the range of frequencies present in the incident light....