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प्रश्न
In torches, search lights and headlights of vehicles the bulb is placed ______.
विकल्प
between the pole and the focus of the reflector
very near to the focus of the reflector
between the focus and centre of curvature of the reflector
at the centre of curvature of the reflector
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उत्तर
In torches, search lights and headlights of vehicles the bulb is placed very near to the focus of the reflector.
Explanation -
In torches, search lights and headlights of vehicles concave mirrors are used. When a light source is placed at the focus of the mirror, after reflection light rays become parallel to the principal axis. Due to this, the bulb is placed very near to the focus of the reflector.
संबंधित प्रश्न
Explain the following term related to spherical lenses:- optical centre
Define the following term in the context of spherical mirrors:- Pole
The letter F is placed in front of a plane mirror:
What is the name of the phenomenon involved?
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.
At which point of the spherical mirror the carbon paper is placed?
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.
How is a spherical mirror used to converge a beam of light at a point? Name the type of mirror used.
Mention the types of mirrors used as (i) rear view mirrors, (ii) shaving mirrors. List two reasons to justify your answers in each case.
A student obtained a sharp image of a burning candle, placed at the farther end of a laboratory table, on a screen using a concave mirror. For getting better value of focal length of the mirror, the subject teacher suggested him for focusing a well illuminated distant object. What should the student do?
(A) He should move the mirror away from the screen.
(B) He should move the mirror slightly towards the screen.
(C) He should move the mirror as well as the screen towards the newly selected object.
(D) He should move only the screen towards the newly selected object.
What is a spherical mirror?
A point light source is kept in front of a convex mirror at a distance of 40 cm. The focal length of the mirror is 40 cm. Find the position of image.
Draw a ray diagram to show that a convex mirror has a wider field of view.
What is the difference between virtual images of an object formed by a concave mirror and a convex mirror?
A converging lens of focal length f is placed at a distance 0.3 m from an object to produce an image on a screen 0.9 m from the lens. With the object and the screen in the same positions, an image of the object could also be produced on the screen by placing a converging lens of focal length.
