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प्रश्न
Which type of mirror is used in the following?
Floodlights
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उत्तर
Concave mirror
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संबंधित प्रश्न
To construct ray diagrams, two rays of light are generally so chosen that it is easy to determine their directions after reflection from a mirror. Choose two such rays and state the path/direction of these rays after reflection from a concave mirror. Use these two rays to find the position and nature of the image of an object placed at a distance of 8 cm from a concave mirror of focal length 12 cm.
Three students A, B and C focussed a distant building on a screen with the help of a concave mirror. To determine focal length of the concave mirror they measured the distances as given below:
Student A : From mirror to the screen
Student B : From building to the screen
Student C : From building to the mirror
Who measured the focal length correctly ;
(a) Only A
(b) Only B
(c) A and B
(d) B and C
The image of a candle flame placed at a distance of 30 cm from a mirror is formed on a screen placed in front of the mirror at a distance of 60 cm from its pole. What is the nature of the mirror? Find its focal length. If the height of the flame is 2.4 cm, find the height of its image. State whether the image formed is erect or inverted.
The angle between an incident ray and the plane mirror is 30°. The total angle between the incident ray and reflected ray will be:
(a) 30°
(b) 60°
(c) 90°
(d) 120°
Fill in the following blank with suitable word:
The focal length of a concave mirror is the distance from the ......... to the mirror.
Define (i) principal focus of a concave mirror, and (ii) focal length of a concave mirror.
Explain why, a ray of light passing through the centre of curvature of a concave mirror gets reflected back along the same path.
The real image formed by a concave mirror is smaller than the object if the object is:
(a) between centre of curvature and focus
(b) at a distance greater than radius of curvature
(c) at a distance equal to radius of curvature
(d) at a distance equal to focal length
The angle of incidence for of light passing through the centre of curvature of a concave mirror is:
(a) 45°
(b) 90°
(c) 0°
(d) 180°
In the concave reflector of a torch, the bulb is placed:
(a) between the pole and focus of reflector
(b) at the focus of reflector
(c) between focus and centre of curvature of reflector
(d) at the centre of curvature of reflector
According to the "New Cartesian Singh Convention" for mirrors, what sign has been given to the focal length of:
a convex mirror?
According to New Cartesian Sign Convention:
(a) focal length of concave mirror is positive and that of convex mirror is negative
(b) focal length of both concave and convex mirrors is positive
(c) focal length of both concave and convex mirrors is negative
(d) focal length of concave mirror is negative and that of convex mirror is positive
Describe the nature of image formed when the object is placed at a distance of 20 cm from a concave mirror of focal length 10 cm
A concave mirror produces a real image 1 cm tall of an object 2.5 mm tall placed 5 cm from the mirror. Find the position of the image and the focal length of the mirror.
An object is 24 cm away from a concave mirror and its image is 16 cm from the mirror. Find the focal length and radius of curvature of the mirror, and the magnification of the image.
Draw and complete the following diagrams to show what happens to the beams of light as they enter the glass block and then leave it:
With the help of a labelled diagram, explain how a concave lens diverges a beam of parallel light rays. Mark the principal axis, optical centre, principal focus and focal length of the concave lens on the diagram.
Which of the following can make a parallel beam of light from a bulb falls on it?
(a) concave mirror as well as concave lens
(b) convex mirror as well as concave lens
(c) concave mirror as well as convex lens
(d) concave mirror as well as convex lens
A concave mirror produces a magnification of +4. The object is placed ______.
What is a concave and convex mirror?
