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प्रश्न
A _____________ mirror is used by a dentist.
पर्याय
concave
convex
plane
none of the above.
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उत्तर
A concave mirror is used by a dentist.
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संबंधित प्रश्न
An object of height 5 cm is placed perpendicular to the principal axis of a concave lens of focal length 10 cm. If the distance of the object from the optical centre of the lens is 20 cm, determine the position, nature and size of the image formed using the lens formula.
State two positions in which a concave mirror produces a magnified image of a given object. List two differences between the two images.
Draw ray diagrams to show the principal focus of a concave mirror.
The radius of curvature of a spherical mirror is 20 cm. What is its focal length?
An object of size 7.0 cm is placed at 27 cm in front of a concave mirror of focal length 18 cm. At what distance from the mirror should a screen be placed, so that a sharp focused image can be obtained? Find the size and the nature of the image.
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°
A concave mirror ______ rays of light whereas a convex mirror ______ rays of light.
Described with the help of a diagram, the nature, size and position of the image formed when an object is placed beyond the centre of curvature of a concave mirror.
between its pole and focus
Describe the nature, size and position of the image formed in each case.
State one use of concave mirror bases on the formation of image as in case (i) above.
The real image formed by a concave mirror is larger than the object when object is:
(a) at a distance equal to radius of curvature
(b) at a distance less than the focal length
(c) between focus and centre of curvature
(d) at a distance greater than radius of curvature
What kind of mirror can have a focal length of, −20 cm?
One of the following does not apply to a concave mirror this is:
(a) focal length is negative
(b) image distance can be positive or negative
(c) image distance is always positive
(d) height of image can be positive or negative
A converging mirror forms a real image of height 4 cm of an object of height 1 cm placed 20 cm away from the mirror:
- Calculate the image distance.
- What is the focal length of the mirror?
Name the lens which can concentrate sun's rays to a point and burn a hole in a piece of paper.
Why does obtaining the image of the sun on paper with the help of a concave mirror burn the paper?
Concave mirrors are used by dentists to examine teeth. Why?
Under which of the following conditions a concave mirror can form an image larger than the actual object?
A concave mirror produces a magnification of +4. The object is placed ______.
The image formed by concave mirror is real, inverted and of the same size as that of the object. The position of object should be ______.
While looking at the above diagram, Nalini concluded the following.
- the image of the object will be a virtual one.
- the reflected ray will travel along the same path as the incident ray but in opposite direction.
- the image of the object will be inverted.
- this is a concave mirror and hence the focal length will be negative.
Which one of the above statements are correct?
