Mirror Formula and Magnification

Q.

At what distance from a concave mirror of focal length 10 cm should an object 2 cm long be placed in order to get an erect image 6 cm tall ?

Q.

A convex mirror used as rear view mirror on an automobile has a radius of curvature of 3.00 m. If a bus is located at 5.00 m from this mirror, find the position, nature and size of the image.

Q.

When an object is placed 20 cm from a concave mirror, a real image magnified three times is formed. Find : (a) the focal length of the mirror. (b) Where must the object be placed to give a virtual image three times the height of the object ?

Q.

When an object is placed at a distance of 50 cm from a concave spherical mirror, the magnification produced is, -$\frac{1}{2}$ . Where should the object be placed to get a magnification of, - $\frac{1}{5}$ ?

Q.

Question 7
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.

Q.

A dentist's mirror has a radius of curvature of 3 cm. How far must it be placed from a small dental cavity to give a virtual image of the cavity that is magnified five times ?

Q.

How far should an object be placed from the pole of a converging mirror of focal length 20 cm to form a real image of the size exactly $\frac{1}{4}$th the size of the object ?

Q.

A concave mirror produces a real image 1 cm tall of an object 2.5 mm tall placed 5 cm from the mirror. Find the position of the image and the focal length of the mirror.

Q.

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 ?

Q.

An object is placed at a distance of 10 cm from a concave mirror of focal length 20 cm. (a) Draw a ray diagram for the formation of image. (b) Calculate the image distance. (c) State two characteristics of the image formed.

Q.

If an object of 10 cm height is placed at a distance of 36 cm from a concave mirror of focal length 12 cm, find the position, nature and height of the image.

Q.

When an object is placed at a distance of 15 cm from a concave mirror, its image is formed at 10 cm in front of the mirror. Calculate the focal length of the mirror.

Q.

An object 5 cm high is placed at a distance of 10cm from a convex mirror whose radius of curvature is 30 cm. Find the nature, position and size of the image.

Q.

A converging mirror forms a real image of height 4 cm of an object of height 1 cm placed 20 cm away from the mirror : (1) Calculate the image distance. (ii) What is the focal length of the mirror ?

Q.

A diverging mirror of radius of curvature 40 cm forms an image which is half the height of the object. Find the object and image positions.

Q.

A concave mirror produces three times enlarged virtual image of an object placed at 10 cm in front of it. Calculate the radius of curvature of the mirror.

Q.

6. a.An object 4 cm in size is placed at a distance of 25 cm from a concave mirror of focal
length 15 cm. Find the position, nature and height of the image.
b A converging mirror forms a real image of height 4 cm, of an object of height 1 cm
placed 20 cm away from the mirror. Calculate the image distance. What is the focal
length of the mirror?

Q.

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 of : ( (a) 20 cm (b) 30 cm c) 40 cm (d) 50 cm

Q.

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 ?

Q.

A concave mirror produces three times enlarged image of an object placed $10cm$ in front of it. Calculate the focal length of the mirror $\frac{-v}{u}$.

Q.

A mirror forms an image which is 30 cm from an object and twice its height.

(a) Where must the mirror be situated?

(b) What is the radius of curvature?

(c) Is the mirror convex or concave?

Q.

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 ?

Q. An erect image 3 times the size of the object is obtained with a concave mirror of radius of curvature 36cm. What is the position of the object?

1. 15cm
2. 20cm
3. 12cm
4. 30cm

Q.

An object of 5.0 cm size is placed at a distance of 20.0 cm from a converging mirror of focal length 15.0 cm. At what distance from the mirror should a screen be placed to get the sharp image ? Also calculate the size of the image.

Q.

An object is placed (a) 20 cm, (b) 4 cm, in front of a concave mirror of focal length 12 cm. Find the nature and position of the image formed in each case.

Q.

At what distance from a concave mirror of focal length 10 cm should an object be placed so that : (a) its real image is formed 20 cm from the mirror ? (b) its virtual image is formed 20 cm from the mirror ?

Q.

Enlist the uses of spherical Mirrors.

Q.

A man holds a spherical shaving mirror of radius of curvature 60 cm, and focal length 30 cm, a t a distance of 15 cm, from his nose. Find the position of image, and calculate the magnification.

Q. Question 6
Which of the following lenses would you prefer to use while reading small letters found in a dictionary?

(a) A convex lens of focal length 50 cm
(b) A concave lens of focal length 50 cm
(c) A convex lens of focal length 5 cm
(d) A concave lens of focal length 5 cm

Q.

An object 3 cm high is placed at a distance of 10 cm in front of a converging mirror of focal length 20 cm. Find the position, nature and size of the image formed.