The focal length of a concave mirror is f and the distance of the object from the principal focus is x, the magnification of the image produced is
fx
f/x
x/f
1/xf
A spherical mirror produces lateral magnification M what is the longitudinal magnification produced by it?
M2
M
M1/2
M3/2
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.
Critical angle of light passing from glass to air is minimum for?
red colour
green colour
yellow colour
blue colour
A convex lens produces a real image m times the size of the object. What is the distance of the object from the lens?
(m+1)f/m
(m-1)f/m
(m-1) f
(m+1)f
What is the minimum distance between the object and its real image in case of as convex lens?
0
f
2f
4f
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
A biconvex lens behaves as diverging lens in water and a converging lens in air. The refractive index of water is 1.33 and that of air is 1. What can we say above the refractive index n of the material of lens?
n < 0
0<n<1
1<n<1.33
n>1.33
Out of the following which colour a monochromatic beam cannot be obtained
Red
Green
Blue
White
The object is placed at a distance n times the focal length of a concave lens. The linear magnification the object is
1/ (n+1)
(1/n)+1
1/ (n-1)
(1/n)-1