Radius of curvature, r =
f/2
2f
2/3 f
f
Which type of mirror is used in box-type solar cooker?
Spherical mirror
Convex mirror
Plane mirror
Concave mirror
An image formed by a plane mirror is a/an
Virtual image
Areal image
Inverted image
None of these
Which of the following is transparent ?
Stone
Wood
Plastic
Glass
Opaque objects
allow the light to pass through them.
do not let the light to pass through them.
absorb some amount of light and let the remaining to pass through them.
allows the light from natural sources and rejects if it is from artificial sources.
Light is a form of energy that causes the sensation of
hearing
heat
sight
touch
Sunlight on earth is
convergent
divergent
parallel
irregular
Nature of the shadow depends on
the relative distance between the source of light and the object
the relative size of the source of light and the object
the angle between the source of light and the object
all of the above
The natural source of light is
Sun
Electric lamp
Candle flame
Kerosene lamp
Umbra is a region of
complete darkness
partial darkness
partial brightness
complete brightness
