The distance between the object and its real image formed by a concave mirror is minimum when the distance of the object from the centre of curvature of the mirror is: [f focal length of the mirror]
1. Zero
2.
3. f
4. 2f
A point object O is placed at a distance 20 cm from a biconvex lens of the radius of curvature 20 cm and \(\mu=1.5.\) The final image produced by lens and mirror combination will be at:
1. | 10 cm from the mirror |
2. | 20 cm from the lens |
3. | - 20 cm from the lens |
4. | -15 cm from the mirror |
In the case of a compound microscope, the image formed by the objective lens is:
1. | Virtual, erect, and diminished. |
2. | Real, erect, and magnified. |
3. | Virtual, inverted, and enlarged. |
4. | Real, inverted, and enlarged. |
Two slabs P & Q of transparent materials have a thickness in the ratio 2 : 5. If a ray of light takes the same amount of time to move from A to B and B to C, then the refractive index of Q with respect to P will be:
1. 0.4
2. 2.5
3. 1.4
4. 1.85
In the following diagram, what is the distance x if the radius of curvature is R = 15 cm?
1. 30 cm
2. 20 cm
3. 15 cm
4. 10 cm
In the diagram shown below, the image of the point object O is formed at \(l\) by the convex lens of focal length 20 cm, where \(F_1\) and \(F_2\) are foci of the lens. The value of \(x'\) is:
1. | 10 cm | 2. | 20 cm |
3. | 30 cm | 4. | 40 cm |
A glass slab is placed with the right-angled prism as shown in the figure. The possible value of \(\theta\) such that light incident normally on the prism does not pass through the glass slab is:
1. | \(30^\circ\) | 2. | \(37^\circ\) |
3. | \(45^\circ\) | 4. | Both (1) & (2) |
A graph is plotted between the angle of deviation \(\delta\) in a triangular prism and the angle of incidence as shown in the figure. Refracting angle of the prism is:
1. | \(28^\circ~\) | 2. | \(48^\circ~\) |
3. | \(36^\circ~\) | 4. | \(46^\circ~\) |
Three identical thin convex lenses are kept as shown in the figure. A ray passing through the lens is shown. The focal length of each lens is:
1. | 5 cm | 2. | 10 cm |
3. | 15 cm | 4. | 20 cm |
The following diagram shows a glass sphere of radius \(10~\mathrm{cm}\) with a paraxial incident ray. The refractive index of the material of the glass is:
1. 2
2. 1.5
3. 1.75
4. 1.3