Advertisements
Advertisements
प्रश्न
When a spherical mirror is held towards the sun and its sharp image is formed on a piece of a carbon paper for some time, a hole is burnt in the carbon paper.
Why is a hole burnt in the carbon paper?
Advertisements
उत्तर
A concave mirror converges light rays, and in this case it will converge the incoming parallel rays of the sun at its focus. Since the carbon paper was kept at the focus of the concave mirror, the hole was burnt into it.
APPEARS IN
संबंधित प्रश्न
Explain the following term related to spherical lenses: focal length
Give one use each of a concave and a convex mirror.
A virtual image larger than the object can be produced by a ______.
What kind of mirror is required for obtaining a virtual image of the same size as the object?
A small object is placed 150 mm away from a diverging lens of focal length 100 mm.
(i) Copy the figure below and draw rays to show how an image is formed by the lens.
Figure
(ii) Calculate the distance of the image from the lens by using the lens formula.
A ray of light travels from a denser medium to a rarer medium. How will it bend?
Explain the following terms :
Pole, Centre of curvature, Radius of curvature, Principal axis. Show them on separate diagrams for each of the concave and convex mirrors.
Name the kind of mirror used to obtain
(a) a real and enlarged image
(b) a virtual and enlarged image
(c) a real and diminished image, and
(d) a virtual and diminished image.
In each case (a) and (b), draw reflected rays for the given incident rays and mark focus by the symbol F.
Why does a driver use a convex mirror instead of a plane mirror as a rear view mirror?
Illustrate your answer with the help of a ray diagram.
Which mirror will you prefer to use as a rear view mirror in a car : plane mirror or convex mirror? Give one reason.
The image formed by a convex mirror is
The focal length of a concave mirror is 10 cm. Find its radius of curvature.
An object of height 2 cm is placed at a distance of 20 cm in front of a concave mirror of a focal length of 12 cm. Find the position, size, and nature of the image.
Select the correct option:
A concave mirror is made by cutting a portion of a hollow glass sphere of radius 30 cm. The focal length of the concave mirror is:
Define the term Aperture.
Complete the following diagrams shown in the following figures by drawing the reflected rays.
Assertion: Incident ray is directed towards the centre of curvature of spherical mirror. After reflection it retraces its path.
Reason: Angle of incidence (i) = Angle of reflection (r) = 0°
