1. A ray of light
strikes the surface of mirror at an angle of 300 with the
mirror. The angle of reflection is:
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(a) 300
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(b) 600
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(c) 450
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(d) none.
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2. An object 20cm high is placed at a distance of 100 cm from a plane mirror .The size of the image will be. |
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(a) 20 cm
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(b) 40cm
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(c) 10cm
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(d) 100cm
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3. Velocity of light in vacuum is |
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(a)3×108 cm/s
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(b)3×108 km/s
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(c)3×108m/s
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(d)none of these
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4. A concave mirror is a part of a sphere of radius 30cm.It’s focal length is | |||||||
(a) at infinity
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(b)10cm
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(c)15cm
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(d) 60cm
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5. Magnification produced by a plane mirror is |
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(a)-1
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(b) zero
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(c) +1
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(d) infinity
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6. Mirror used for focusing light is |
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(a) Concave
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(b) Convex
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(c) plane
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(d) none
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7. A concave mirror forms a real and enlarged image of an object if the object is placed at/between |
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(a) 2F
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(b) F
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(c) F and C
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(d)F and P
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8. Focal length of a plane mirror is |
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(a) zero
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(b)infinity
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(c)double of its aperture
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(d)half of its aperture
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9. Sin C = |
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(a) n/1
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(b) 1/n
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(c) n2
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(d)n/2
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10. When a ray of light is incident normally, the angle of incidence is |
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(a) 900
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(b) 0
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(c) 450
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(d) none
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11. A stick in water appears broken due to |
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(a) reflection of light
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(b) refraction of light
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(c) total internal reflection
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(d) none of these
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12. If angle of incidence is 00 then angle of reflection is |
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(a) 900
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(b) 00
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(c)450
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(d)600
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13. Refractive index of diamond with respect to vacuum is 2.5, and then the velocity of light in diamond is. |
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(a) 25×108 m/s
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(b)2.5×108 m/s
|
(c)1.2×108 m/s
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(d)2.1×108m/s
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14. Critical angle of a substance is 300.It’s refractive index is |
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(a)0.2
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(b) 2
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(c)0.5
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(d)2.5
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15. Velocity of light in diamond is | |||||||
(a)2.1×108
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(b)1.2×108
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(c)1.5×108
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(d)2.5×108
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16. When a ray goes from an optically rarer medium to a denser medium, it |
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(a) goes straight
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(b)bends away from normal
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(c) bends towards normal
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(d) reflect back
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17. Lateral displacement is directly proportional to: | |||||||
(a) Angle of incidence
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(b) angle of refraction
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(c) Thickness of the slab
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(d) velocity of light
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18. n×sinC= |
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(a) zero
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(b)1
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(c)infinity
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(d) none of these
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19.To a fish, the plane surface of earth appears to be enclosed within an angle of | |||||||
(a)600
|
(b)1800
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(c)970
|
(d)450
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20. Power of a lens is 2D, it’s focal length is |
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(a)-0.5 m
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(b)50 cm
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(c)150cm
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(d) 50m
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21. The splitting of light into its component colours is called |
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(a) refraction
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(b)spectrum
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(c) dispertion
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(d) diffraction
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22. if ‘i’ is critical angle, ‘r’ is |
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(a) zero
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(b)900
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(c)1800
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(d)450
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23. A drop of water appears like pearl due to |
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(a)refraction (b) none
(c)reflection (d) total internal reflection
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24. curvature of a plane glass is |
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(a)infinity
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(b)zero
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(c) eqal to C
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(d)none
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25. Mayopia can be corrected using |
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(a) concave lens
|
(b)convex lens
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(c) cylindrical lens
|
(d) Plano convex lens
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Answer key
1.b
2.a 3.c 4.c
5.c 6.a
7.c 8.a 9.b 10.b 11.b 12.b
13.c 14.b 15.b 16.c 17.c 18.b
19.c
20.b 21.c 22.b 23.d 24.a
25.a
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