03 December 2011

CBSE NCERT Formative Assessment : MCQ ( Reflection and refraction)

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