Advertisements
Advertisements
प्रश्न
A simple microscope is used by watch repairers. Give reason.
उत्तर
When an object is placed within the focal length of a simple microscope, its magnified and erect image is obtained on the same side of the lens as that of the object. So, a watch repairer sees the minute parts of a watch very clearly with a simple microscope by adjusting the distance between the object and the lens. This helps in repairing the watch. Hence, a simple microscope is used by watch repairers.
APPEARS IN
संबंधित प्रश्न
Explain the following term related to spherical lenses:- principal axis
What is the name of the phenomenon in which the right side of an object appears to be the left side of the image in a plane mirror?
Name the two types of spherical mirrors. What type of mirror is represented by the:
front side of a shining steel spoon?
When a spherical mirror is held towards the sun and its sharp image is formed on a piece of a carbon paper for some time, a hole is burnt in the carbon paper.
Why is a hole burnt in the carbon paper?
When a spherical mirror is held towards the sun and its sharp image is formed on a piece of a carbon paper for some time, a hole is burnt in the carbon paper.
What is the advantage of using a carbon paper rather than a white paper?
Complete the following sentence:
All the distances are measured from the .......... of a spherical mirror.
The shiny outer surface of a hollow sphere of aluminium of radius 50 cm is to be used as a mirror:
Which type of spherical mirror will it provide?
A ray of light travels from a denser medium to a rarer medium. How will it bend?
Which are the two convenient rays that are chosen to construct the image by a spherical mirror for a given object? Explain with the help of suitable ray diagrams.
A student obtained on a screen the sharp image of a candle flame placed at the farther end of laboratory table using a concave mirror. For getting better value of focal length of the mirror, the teacher suggested to him to focus the sun. What should the student do?
(A) Should move the mirror away from the screen.
(B) Should move the mirror towards the screen.
(C) Should move the mirror and screen both towards the sun.
(D) Should move only the screen towards the sun.
Explain the meaning of the terms focus and focal length in case of a convex mirror, with the help of suitable ray diagram.
Draw a ray diagram to show the formation of image by a concave mirror for the object beyond its centre of curvature. State three characteristics of the image.
State whether the image in part (a) is real or virtual?
What is meant by magnification? Write its expression. What is its sign for the (a) real (b) virtual, image?
Why does a driver use a convex mirror instead of a plane mirror as a rear view mirror?
Illustrate your answer with the help of a ray diagram.
Draw a ray diagram to show the formation of image of an object kept in front of a convex mirror. State three characteristics of the image.
The radius of curvature of a convex mirror is 40 cm. Find its focal length.
The focal length of a concave mirror is 10 cm. Find its radius of curvature.
The magnification for a mirror is -3. How are u and v related?
Select the correct option:
A concave mirror is made by cutting a portion of a hollow glass sphere of radius 30 cm. The focal length of the concave mirror is:
Select the correct option:
Looking into a mirror one finds her image diminished, the mirror is:
Define the following term in relation to concave mirror.
Principal axis
What is the relation between focal length and radius of curvature of a concave mirror?
Does the mirror name by your form a real image for all locations? Give a reason for your answer.
Find the height of the image of a body of height 1.5m in a mirror with a magnification of 1.5.
The boxes in figure (a, b, c) represent mirrors; insert a mirror which will reflect the incident ray as shown in the diagram.
A concave mirror can be used to produce a parallel beam of light. Draw a ray to illustrate this.
If the focal length of a spherical mirror is 10 cm, what is the value of its radius of curvature?
Numerical problem.
The radius of curvature of a spherical mirror is 25 cm. Find its focal length.
If the real image of a candle flame formed by a lens is three times the size of the flame and the distance between lens and image is 80 cm, at what distance should the candle be placed from the lens?
What is the difference between virtual images of an object formed by a concave mirror and a convex mirror?
