If a light ray is incident normally on face AB of a prism, then for no emergent ray from second face AC:
[refractive index of glass of prism]
1. | \(\mu=\frac{2}{\sqrt{3}}\) | 2. | \(\mu>\frac{2}{\sqrt{3}}\) |
3. | \(\mu<\frac{2}{\sqrt{3}}\) | 4. | μ can have any value. |
In a glass ( = 1.5) sphere with a radius of 10 cm, there is an air bubble B at a distance of 5 cm from C. The distance of the bubble from the surface of the sphere (i.e., point A) as observed from point P in the air will be:
1. | 4.5 cm | 2. | 20.0cm |
3. | 9.37 cm | 4. | 6.67 cm |
A lens forms an image of a point object placed at distance 20 cm from it. The image is formed just in front of the object at a distance 4 cm from the object (and towards the lens). The power of the lens is:
1. 2.25 D
2. 1.75 D
3. 1.25 D
4. 1.4 D
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 |
A person can see objects clearly between 1 m and 3 m. The power of lens required to correct near point will be:
1. 2.5 D
2. + 3 D
3. + 1.5 D
4. 1.75 D
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 |