1.When light travels from one medium to another, there is no change in its : (a) Velocity (b) Amplitude (c) Frequency (d) Wavelength 2.An object is placed between two plane mirrors set at 600 to each other. The maximum number of images seen will be : (a) 2 (b) 3 (c) 5 (d) 6 3.A band spectrum is produced by : (a) H (b) He (c) H2 (d) Na 4.If the refractive index of water is (4/3) and that of a given slab of glass is (3/2), what will be the refractive index of glass with respect to water ? (a) 7/6 (b) 8/9 (c) 9/8 (d) None of these 5.An air bubble in water will behave as : (a) Convergent lens (b) Divergent lens (c) Plane mirror (d) Plane glass plate 6.A glass prism of refractive index 1.5 is immersed in water ( = 4/3). A light beam incident normally on the face AB is totally reflected to reach the face BC if : (a) sin > 8/9 (b) 2/3 < sin < 8/9 (c) sin 2/3 (d) cos 8/9 7.The deviation produced by a prism is : (a) Same for all wavelengths (b) Greatest for red and least for violet (c) Greatest for violet and least for red (d) Not possible 8.The angle of a prism is60 and this refractive index for green light is 1.5. If a green ray passes through it, the deviation will be : (a) 300 (b) 150 (c) 90 (d) 30 9.If the refracting angle of a prism is 600 and minimum deviation 300, the angle of incidence will be : (a) 300 (b) 450 (c) 600 (d) 900 10.The refracting angle of a prism is ‘A’ and the refractive index of the prism is (A/2). The angle of minimum deviation is : (a) 1800 – 3A (b) 1800 + 2A (c) 900 – A (d) 1800 – 2A 11.Rainbow is seen due to : (a) Interference by thin films (b) Scattering of sunlight (c) Dispersion of sunlight (d) Diffraction of sunlight 12.If the radius of curvature of the convex surface of a thin plano–convex lens is 18 cm and the refractive index of the material of the lens is 1.6, he focal length of the lens is : (a) 18 cm (b) 24 cm (c) 30 cm (d) 40 cm 13.An equi–convex lens has power D. It is cut into two symmetrical halves by a plane containing the principal axis and then two pieces are joined as shown in Fig. The power of the combination will be : (a) P (b) 2P (c) P/2 (d) Zero
Posted on: Fri, 03 Oct 2014 07:32:25 +0000