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प्रश्न
Describe the positions of the source of light with respect to a concave mirror in Floodlight.
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उत्तर
In a floodlight, the light source is slightly beyond the radius of curvature, which gives us the right light.
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संबंधित प्रश्न
If the image formed by a mirror for all positions of the object placed in front of it is always erect and diminished, what type of mirror is it? Draw a ray diagram to justify your answer. Where and why do we generally use this type of mirror?
Draw ray diagrams to show the principal focus of a convex mirror.
List four characteristics of the images formed by plane mirrors.
List four specific characteristics of the images of the objects formed by convex mirrors.
A student wants to project the image of a candle flame on a screen 48 cm in front of a mirror by keeping the flame at a distance of 12 cm from its pole.
(a) Suggest the type of mirror he should use.
(b) Find the linear magnification of the image produced.
(c) How far is the image from its object?
(d) Draw ray diagram to show the image formation in this case.
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.
Draw the following diagram in your answer book and show the formation of image with the help of suitable rays:
What is the minimum number of rays required for locating the image formed by a concave mirror for an object? Draw a ray diagram to show the formation of a virtual image by a concave mirror.
If an object is placed at a distance of 8 cm from a concave mirror of focal length 10 cm, discuss the nature of the image formed by drawing the ray diagram.
State where an object must be placed so that the image formed by a concave mirror is:
(b) at infinity.
(c) the same size as the object.
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
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
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
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?
An object is placed just outside the principal focus of concave mirror. Draw a ray diagram to show how the image is formed, and describe its size, position and nature.
If the object is moved further away from the mirror, what changes are there in the position and size of the image?
An object is placed at a large distance in front of a concave mirror of radius of curvature 40 cm. The image will be formed in front of the mirror at a distance:
(a) 20 cm
(b) 30 cm
(c) 40 cm
(d) 50 cm
What type of image/images are formed by:
a convex mirror?
The mirror used by a dentist to examine the teeth of a person is:
(d) any one of the above
(a) convex
(b) concave
(c) plane
(d) any one of the above
Draw a ray diagram to show the formation of image of an object placed at the centre of curvature of a concave mirror. State the position, size and nature of the image.
Draw a ray diagram to show the formation of image of an object placed between the focus and centre of curvature of a concave mirror. State the position, size and nature of the image.
A student has to trace the path of a ray of light passing through a rectangular glass slab for four different values of angle of incidence.
(a) Write two important precautions for this experiment.
(b) List two conclusions the student will draw based on his experiment.
Why are concave mirrors used in solar devices?
Why does obtaining the image of the sun on paper with the help of a concave mirror burn the paper?
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:
According to cartesion sign convention, which mirror and which lens has negative focal length?
Name the mirror(s) that can give (i) an erect and enlarged image, (ii) same sized, inverted image
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.
The mirror having reflecting surface curved inwards ______.
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 ______.
Which of the following mirror is used by a dentist to examine a small cavity in a patient’s teeth?
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?
An image formed by a lens is erect. Such an image could be formed by a
______ mirrors make things look larger when objects are placed close to them.
In torches, searchlights, and headlights of vehicles, the bulb is placed ______ of the concave mirror.
The focal length of a concave mirror is 5cm. Its radius of curvature is ______.
Write the uses of the concave mirror.
To obtain an image twice the size of the object, between which two points related to a concave mirror should an object be placed?
Which type of mirror is used in the following?
Head lamps of a car
