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प्रश्न
A _____________ mirror is used by a dentist.
पर्याय
concave
convex
plane
none of the above.
उत्तर
A concave mirror is used by a dentist.
APPEARS IN
संबंधित प्रश्न
With the help of an appropriate ray diagram, state the sign conventions for reflection by a spherical mirror.
It is desired to obtain an erect image of an object, using concave mirror of focal length of 12 cm.
What should be the range of distance of an object placed in front of the mirror?
To determine the approximate value of the focal length of a given concave mirror, you focus the image of a distant object formed by the mirror on a screen. The image obtained on the serene, as compared to the object is always:
(a) Laterally inverted and diminished
(b) Inverted and diminished
(c) Erect and diminished
(d) Erect and highly diminished
A spherical mirror produces an image of magnification −1 on a screen placed at a distance of 40 cm from the mirror:
(i) Write the type of mirror.
(ii) What is the nature of the image formed?
(iii) How far is the object located from the mirror?
(iv) Draw the ray diagram to show the image formation in this case.
The radius of curvature of a spherical mirror is 20 cm. What is its focal length?
Name the mirror that can give an erect and enlarged image of an object.
We wish to obtain an erect image of an object, using a concave mirror of focal length 15 cm. What should be the range of distance of the object from the mirror? What is the nature of the image? Is the image larger or smaller than the object? Draw a ray diagram to show the image formation in this case.
To construct a ray diagram we use two rays which are so chosen that it is easy to know their directions after reflection from the mirror. List two such rays and state the path of these rays after reflection in case of concave mirrors. Use these two rays and draw ray diagram to locate the image of an object placed between pole and focus of a concave mirror.
ill in the following blank with suitable word:
For a convex mirror, parallel rays of light appear to diverge from a point called the ......... .
Draw diagram to represent the action of a concave mirror on a beam of parallel light rays. Mark on this diagram principal axis, focus F, centre of curvature C, pole P and focal length f, of the concave mirror.
If an object is at infinity (very large distance) in front of a concave mirror, where is the image formed?
Draw ray-diagrams to show the formation of images when the object is places in front of a concave mirror (converging mirror):
(i) between its pole and focus
(ii) between its centre of curvature and focus
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
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
What kind of mirror can have a focal length of, −20 cm?
What is the position of the image when an object is placed at a distance of 20 cm from a concave mirror of focal length 20 cm?
A bright object 50 mm high stands on the axis of a concave mirror of focal length 100 mm and at a distance of 300 mm from the concave mirror. How big will the image be?
How far should an object be placed from the pole of a converging mirror of focal length 20cm to form a real image of the size exactly `1/4`th the size of the object?
Name the mirror which can give:
an erect and enlarged image of an object.
A concave mirror cannot be used as:
(a) a magnifying mirror
(b) a torch reflector
(c) a dentist's mirror
(d) a real view mirror
The mirror which can form a magnified image of an object is:
(a) convex mirror
(b) plane mirror
(c) concave mirror
(d) both convex and concave mirror
Radius of curvature of a spherical mirror is ............. its focal length.
The image formed by a concave mirror is of the same size as the object, if the object is placed
Draw a ray diagram to show the formation of image of an object placed between the pole and focus of a concave mirror. State the position, size and nature of the image.
A student has focused the image of a candle flame on a white screen using a concave mirror. The situation is as given below:
Length of the flame = 1.5 cm
Distance of flame from the mirror = 18 cm
If the flame is perpendicular to the principal axis of the mirror, then calculate the following:
- Distance of the image from the mirror
- Length of the image
If the distance between the mirror and the flame is reduced to 10 cm, then what would be observed on the screen? Draw ray diagram to justify your answer for this situation.
Why does obtaining the image of the sun on paper with the help of a concave mirror burn the paper?
In which equipment/s do you find ___________________
List four characteristics of the image formed by a concave mirror of focal length 40 cm when the object is placed in front of it at a distance of 20 cm from its pole.
The radius of curvature of a concave mirror whose focal length is 5cm is ______
Name the mirror(s) that can give (i) an erect and enlarged image, (ii) same sized, inverted image
Concave mirrors are used by dentists to examine teeth. Why?
Pick out the concave and convex mirrors from the following and tabulate them.
Rear-view mirror, Dentist’s mirror, Torchlight mirror, Mirrors in shopping malls, Make-up mirror.
A 10 mm long awl pin is placed vertically in front of a concave mirror. A 5 mm long image of the awl pin is formed at 30 cm in front of the mirror. The focal length of this mirror is ______.
In which of the following, the image of an object placed at infinity will be highly diminished and point sized?
A concave mirror produces a magnification of +4. The object is placed ______.
Which of the following mirror is used by a dentist to examine a small cavity in a patient’s teeth?
The focal length of a concave mirror is 5cm. Its radius of curvature is ______.
