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प्रश्न
According to cartesion sign convention, which mirror and which lens has negative focal length?
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उत्तर
Concave mirror is having a negative focal length.
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संबंधित प्रश्न
Out of convex mirror and concave mirror, whose focus is situated behind the mirror?
A communications satellite in orbit sends a parallel beam of signals down to earth. If these signals obey the same laws of reflection as light and are to be focussed onto a small receiving aerial, what should be the best shape of the metal 'dish' used to collect them?
Make labelled ray diagrams to illustrate the formation of:
- a real image by a converging mirror.
- a virtual image by a converging mirror.
Mark clearly the pole, focus, centre of curvature and position of object in each case.
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°
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
The image formed by a concave mirror is of the same size as the object, if the object is placed
Consider the following properties of virtual images:
- cannot be projected on the screen
- are formed by both concave and convex lens
- are always erect
- are always inverted
The correct properties are:
Which of the following ray diagrams is correct for the ray of light incident on a concave mirror as shown in figure?
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| A | B | C | D |
Rays from Sun converge at a point 15 cm in front of a concave mirror. Where should an object be placed so that size of its image is equal to the size of the object?
Which type of mirror is used in the following?
Shaving mirror
