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प्रश्न
Describe the positions of the source of light with respect to a concave mirror in Projector lamp.
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उत्तर
In a projector lamp, the light source is at the centre of the curvature of a concave mirror, which produces an image of the shape of the object itself.
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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?
State two positions in which a concave mirror produces a magnified image of a given object. List two differences between the two images.
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.
A student wants to project the image of a candle flame on the walls of the school laboratory by using a mirror.
(a) Which type of mirror should he use and why?
(b) At what distance, in terms of focal length 'f' of the mirror, should he place the candle flame to get the magnified image on the wall?
(c) Draw a ray diagram to show the formation of the image in this case.
(d) Can he use this mirror to project a diminished image of the candle flame on the same wall? State 'how' if your answer is 'yes' and 'why not' if your answer is 'no.'
Name the mirror that can give an erect and enlarged image of an object.
A concave mirror produces three times magnified image on a screen. If the object is placed 20 cm in front of the mirror, how far is the screen from the object.
Which type of mirror is used by a dentist?
Define the principal focus of a concave mirror.
Explain why, a ray of light passing through the centre of curvature of a concave mirror gets reflected back along the same path.
With the help of a ray diagram, determine the position, nature and size of the image formed of an object placed at the centre of curvature of a concave mirror.
Which mirror is used as a torch reflector? Draw a labelled diagram to show how a torch reflector can be used to produce a parallel beam of light. Where is the bulb placed in relation to the torch reflector?
Make labelled ray diagrams to illustrate the formation of:
a virtual image by a converging mirror.
Mark clearly the pole, focus, centre of curvature and position of object in each case.
Name the type of mirror used by dentists. How does it help?
Give two uses of concave mirrors. Explain why you would choose concave mirrors for these uses.
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 image formed by a concave mirror is real, inverted and highly diminished (much smaller than the object). The object must be:
(a) between pole and focus
(b) at focus
(c) at the centre of curvature
(d) at infinity
An object is 100 mm in front of a concave mirror which produces an upright (erect image). The radius of curvature of the mirror is ______.
A concave mirror has a focal length of 25 cm. At which of the following distance should a person hold his face from this concave mirror so that it may act as a shaving mirror?
(a) 45 cm
(b) 20 cm
(c) 25 cm
(d) 30 cm
Give reason for your choice.
An object is placed at the following distances from a concave mirror of focal length 15 cm, turn by turn:
(a) 35 cm
(b) 30 cm
(c) 20 cm
(d) 10 cm
Which position of the object will produce:
(i) a magnified real image?
(ii) a magnified virtual image?
(iii) a diminished real image?
(iv) an image of same size as the object?
According to the "New Cartesian Singh Convention" for mirrors, what sign has been given to the focal length of:
a convex mirror?
Giving reasons, state the 'signs' (positive or negative) which can be given to the following:
(a) object distance (u) for a concave mirror or convex mirror
(b) image distance (v) for a concave mirror
(c) image distance (v) for a convex mirror
An object is placed at a distance of 10 cm from a concave mirror of focal length 20 cm.
State two characteristics of the image formed.
At what distance from a concave mirror focal length 10 cm should an object 2 cm long be placed in order to get an erect image 6 cm tall?
A man holds a spherical shaving mirror of radius of curvature 60 cm, and focal length 30 cm, at a distance of 15 cm, from his nose. Find the position of image, and calculate the magnification.
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.
Draw and complete the following diagrams to show what happens to the beams of light as they enter the glass block and then leave it:
Name the lens which can concentrate sun's rays to a point and burn a hole in a piece of paper.
Explain the images formed by a concave mirror.
______ is used as reflectors in torchlight.
State whether true or false. If false, correct the statement.
When an object is at the centre of curvature of concave mirror the image formed will be virtual and erect.
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.
Which of the following can make a parallel beam of light when light from a point source is incident on it?
A concave mirror produces a magnification of +4. The object is placed ______.
For a real object, which of the following can produce a real image?
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?
In the headlights of motor vehicles, ______ mirrors are used as reflectors.
Which type of mirror is used in the following?
Floodlights
