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WorksheetsRay Optics
Total questions: 10
Worksheet time: 5mins
The radius of curvature for a convex lens is 40 cm, for each surface. Its refractive index is 1.5. The focal length will be
40
50
34
80
A thin lens focal length f1 and its aperture has diameter d. It forms an image of intensity I. Now the central part of the aperture upto diameter d2 is blocked by an opaque paper. The focal length and image intensity will change to
3f/4 and I/3
f/2 and I/2
F and I
F and 3I/4
A lens of power + 2 diopters is placed in contact with a lens of power - 1 diopter. The combination will behave like
A convergent lens of focal length 50 cm
A convergent lens of focal length 100 cm
A divergent lens of focal length 100 cm
A convergent lens of focal length 200 cm
To an observer on the earth the stars appear to twinkle. This can be ascribed to
The fact that stars do not emit light continuously
Frequent absorption of star light by their own atmosphere
Frequent absorption of star light by the earth's atmosphere
The refractive index fluctuations in the earth's atmosphere
When light travels from one medium to the other of which the refractive index is different, then which of the following will change
Frequency, wavelength and velocity
Frequency and wavelength
Frequency and velocity
Wavelength and velocity
A beam of light propagating in medium A with index of refraction n passes across an interface into medium B with index of refraction n. The angle of incidence is greater than the angle of refraction; v and v denotes the speed of light in A and B. Then which of the following is true
v < v and n < n
v < v and n > n
v > v and n < n
v > v and n > n
A rectangular tank of depth 8 meter is full of water (μ=4/3), the bottom is seen at the depth
6m
10cm
8cm
6/8 m
A diminished virtual image can be formed only in
Concave-parabolic mirror
A convex mirror
Concave lens
Plane mirror
An object 5cm tall is placed 1m from a concave spherical mirror which has a radius of curvature of 20cm The size of the image is
9 cm
0.50 cm
0.55 cm
0.45 cm
The focal length of a concave mirror is 50cm. Where an object be placed so that its image is two times and inverted
75 cm
90 cm
65 cm
25 cm
None of the above
