CBSE
Multiple Choice QuestionsThe refractive indices of glass and quartz w.r.t. air are 3/2 and 12/5 respectively. The refractive index of quartz w.r.t. glass is
8/5
5/8
5/18
18/5
The radius of curvature of concave mirror is 24 cm and the image is magnified by 1.5 times. The object distance is
20 cm
8 cm
16 cm
24 cm
The distance between an object and a divergent lens is m times the focal length of the lens. The linear magnification produced by the lens is
m
m + 1
In a compound microscope, the intermediate image is
virtual, erect and magnified
real, erect and magnified
real, inverted and magnified
virtual, erect and reduced
A point source of light is kept at a depth of h in water of refractive index 4/ 3. The radius of the circle at the surface of water through which light emits is
If n1 and n2 are the refractive indices of the core and the cladding respectively of an optic fibre, then
n1 = n2
n1 < n2
n2 < n1
n2 = 2 n1
The magnification of the image when an object is placed at a distance x from the principal focus of a mirror of focal length f is
Two thin lenses of focal length 20 cm and 25 cm are in contact. The effective power of the combination is
4.5 D
18 D
45 D
9 D
Time taken by sunlight to pass through a window of thickness 4 mm whose refractive index is is
2 × 10-4 s
2 × 104 s
2 × 10-11 s
2 × 1011 s
A ray of light passes through an equilateral prism such that an angle of incidence is equal to the angle of emergence and the latter is equal to th the angle of prism. The angle of deviation is
45°
39°
20°
30°
