A beam of light is converging towards a point on a screen. A plane parallel plate of glass of thickness in the direction of beam= t, refractive index = μ is introduced in the path of the beam. The convergence point is shifted by
t(μ-1)
t(μ+1)
t (1-1/μ)
t (1+1/μ)
Which one of the following is incorrect statement about a photon?
Photon‘s rest mass is zero
Photon?s momentum is hv/c
Photon?s energy is hv
Photons exert no pressure
It is desired to photograph the image of an object placed at a distance 3m from the plane mirror.The camera,which is at a distance of 4.5m from the mirror should be focussed for a distance of:
3m
4.5m
6m
7.5m
A light bulb is placed between two plane mirrors inclined at an angle of 60o.The number of images formed are :
6
2
5
7
A beam of light passes from air to glass, how does the speed of light vary?
decreases
increases
remains unchanged
It may decrease or increase depending upon the colour.
Light goes from medium M1 to the medium M2. In which of the following cases, we are likely to get the weakest refracted beam?
M1= glass, M2= diamond
M1= Water, M2= glass
M1= water, M2= diamond
M1= diamond, M2= glass.
We have a right angled isosceles prism. Its refractive index is 1.5. If we incident a ray normally on one of the two perpendicular surfaces, which of the following phenomena will take place?
dispersion
total internal reflection
refraction
none of the above
A thin rod of length 10cm is placed along the axis of a concave mirror of local length 30cm,such that its real image just touches the rod.What is the length of the image?
5cm
15cm
25cm
75cm
A double convex lens of focal length. F is cut into 4 equivalent parts. Both the parts are mutually perpendicular and parallel to the principal axis. What is the focal length of the each part?
f/2
f
2f
4f
If in a plano convex lens radius of curvature of convex surface is 10cm and the focal length of the lens is 30cm, the refractive index of the material of the lens will be.
1.5
1.66
1.33
3
