A concave mirror of focal length \(100\) cm is used to obtain the image of the sun which subtends an angle of \(30'.\) The diameter of the image of the sun will be:
1. \(1.74\) cm
2. \(0.87\) cm
3. \(0.435\) cm
4. \(100\) cm
A square of side 3 cm is placed at a distance of 25 cm from a concave mirror of focal length 10 cm. The centre of the square is at the axis of the mirror and the plane is normal to the axis. The area enclosed by the image of the square is:
1. | \(4 \mathrm{~cm}^2 \) | 2. | \(6 \mathrm{~cm}^2 \) |
3. | \(16 \mathrm{~cm}^2 \) | 4. | \(36 \mathrm{~cm}^2 \) |
In an experiment of find the focal length of a concave mirror a graph is drawn between the magnitudes of u and v. The graph looks like
As the position of an object (u) reflected from a concave mirror is varied, the position of the image (v) also varies. By letting the u change from 0 to infinity, the graph between v versus u will be-
1. | 2. | ||
3. | 4. |
The graph between u and v for a convex mirror is:
1. | 2. | ||
3. | 4. |
For a concave mirror, if the virtual image is formed, the graph between m and u is of the form :
A point object is moving on the principal axis of a concave mirror of focal length 24 cm towards the mirror. When it is at a distance of 60 cm from the mirror, its velocity is 9 cm/sec. What is the velocity of the image at that instant?
1. | 5 cm/sec towards the mirror |
2. | 4 cm/sec towards the mirror |
3. | 4 cm/sec away from the mirror |
4. | 9 cm/sec away from the mirror |
Match the corresponding entries of Column 1 with Column 2. [Where m is the magnification produced by the mirror]
Column 1 Column 2
A. m=-2 a. Convex mirror
B. m=-1/2 b. Concave mirror
C. m=+2 c. Real image
D. m=+1/2 d. Virtual Image
(1)A->a and c;B->a and d; C->a and b; D->c and d
(2)A->a and d; B->b and c; C->b and d; D-> b and c
(3)A->c and d; B->b and d;C->b and c;D->a and d
(4)A->b and c; B->b and c; C->b and d; D->a and d
A rod of length 10 cm lies along the principal axis of a concave mirror of focal length 10 cm in such a way that its end closer to the pole is 20 cm away from the mirror. The length of the image is:
1. | 10 cm | 2. | 15 cm |
3. | 2.5 cm | 4. | 5 cm |
An object is placed at a distance of \(40\) cm from a concave mirror of a focal length of \(15\) cm. If the object is displaced through a distance of \(20\) cm towards the mirror, the displacement of the image will be:
1. | \(30\) cm away from the mirror |
2. | \(36\) cm away from the mirror |
3. | \(30\) cm towards the mirror |
4. | \(36\) cm towards the mirror |