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प्रश्न
Define focal length.
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उत्तर
The distance between the pole and the principal focus is called the focal length (f) of a spherical mirror.
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संबंधित प्रश्न
What type of image is formed:
- in a plane mirror?
- on a cinema screen?
A lens forms a real image 3 cm high of an object 1 cm high. If the separation of object and image is 15 cm, find the focal length of the lens.
Which are the two convenient rays that are chosen to construct the image by a spherical mirror for a given object? Explain with the help of suitable ray diagrams.
For what position of object, the image formed by a concave mirror is magnified and erect?
Draw a ray diagram to show the formation of image of an object kept in front of a convex mirror. State three characteristics of the image.
Draw a ray diagram to show the formation of the image, when the object is placed between optical centre and principal focus of a convex lens.
State the signs and values of magnifications in the above mentioned case.
In the following figure shows a concave mirror with its pole (P), focus (F) and centre of curvature (C). Draw a ray diagram to show the formation of the image of an object AB by the concave mirror.
A concave mirror can be used to produce a parallel beam of light. Draw a ray to illustrate this.
An object 10 cm high is placed at a distance of 20 cm in front of a spherical mirror of focal length 25 cm. By scale drawing find the nature, position, and magnification of the image in the following case:
Convex mirror
