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प्रश्न
Describe the positions of the source of light with respect to a concave mirror in Torch light.
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उत्तर
In a Torch, the light source is at the hub of a concave mirror, which gives you parallel light.
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संबंधित प्रश्न
With the help of an appropriate ray diagram, state the sign conventions for reflection by a spherical 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
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 obtained a sharp image of a candle flame placed at the distant end of the laboratory table on a screen using a concave mirror to determine its focal length. The teacher suggested him to focus a distant building, about 1 km away from the laboratory, for getting more correct value of the focal length. In order to focus the distant building on the same screen, the student should slightly move the
(a) mirror away from the screen
(b) screen away from the mirror
(c) screen towards the mirror
(d) screen towards the building
To construct a ray diagram we use two rays of light which are so chosen that it is easy to determine their directions after reflection from the mirror. Choose these two rays and state the path of these rays after reflection from a concave mirror. Use these two rays to find the nature and position of the image of an object placed at a distance of 15 cm from a concave mirror of focal length 10 cm.
To construct ray diagrams, two rays of light are generally so chosen that it is easy to determine their directions after reflection from a mirror. Choose two such rays and state the path/direction of these rays after reflection from a concave mirror. Use these two rays to find the position and nature of the image of an object placed at a distance of 8 cm from a concave mirror of focal length 12 cm.
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.
Which type of mirror is used by a dentist?
Out of convex mirror and concave mirror, whose focus is situated behind the mirror?
A concave mirror ______ rays of light whereas a convex mirror ______ rays of light.
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?
Draw the following diagram in your answer book and show the formation of image of the object AB with the help of suitable rays:
Which kind of mirror is used in the headlights of a car? Why is it used for this purpose?
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.
With the help of a labelled ray diagram, describe how a converging mirror can be used to give an enlarged upright image of an object.
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.
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.
- Draw a ray diagram for the formation of image.
- Calculate the image distance.
- State two characteristics of the image formed.
An object 3 cm high is placed at a distance of 8 cm from a concave mirror which produces a virtual image 4.5 cm high:
(i) What is the focal length of the mirror?
(ii) What is the position of image?
(iii) Draw a ray-diagram to show the formation of image.
A large concave mirror has a radius of curvature of 1.5 m. A person stands 10 m in front of the mirror. Where is the person's image?
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?
If the object is moved further away from the mirror, what changes are there in the position and size of the image?
Between which two points of concave mirror should an object be placed to obtain a magnification of:
(a) −3
(b) +25
(c) −0.4
Name the lens which can concentrate sun's rays to a point and burn a hole in a piece of paper.
Which of the following can make a parallel beam of light from a bulb falls on it?
(a) concave mirror as well as concave lens
(b) convex mirror as well as concave lens
(c) concave mirror as well as convex lens
(d) concave mirror as well as convex lens
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.
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.
Why are concave mirrors used in solar devices?
In which equipment/s do you find ___________________
Give any two applications of a concave and convex mirror.
Large ______ mirrors are used to concentrate sunlight to produce heat in solar furnaces.
Beams of light are incident through the holes A and B and emerge out of box through the holes C and D respectively as shown in the figure. Which of the following could be inside the box?
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?
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 ENT doctor uses a ______.
______ mirrors make things look larger when objects are placed close to them.
Define principal focus of the concave mirror.
