- 1(current)
Q. No.A concave mirror of the focal length \(f_1\) is placed at a distance of \(d\) from a convex lens of focal length \(f_2\). A beam of light coming from infinity and falling on this convex lens-concave mirror combination returns to infinity. The distance \(d\) must be equal to:
1. \(f_1 +f_2\)
2. \(-f_1 +f_2\)
3. \(2f_1 +f_2\)
3. \(-2f_1 +f_2\)
| 1. | \(\sqrt{2}\) | 2. | \(\sqrt{3}\) |
| 3. | \(\sqrt{3 / 2}\) | 4. | \(\sqrt{4 / 3}\) |
The slab of a refractive index material equal to \(2\) shown in the figure has a curved surface \(APB\) of a radius of curvature of \(10~\text{cm}\) and a plane surface \(CD.\) On the left of \(APB\) is air and on the right of \(CD\) is water with refractive indices as given in the figure. An object \(O\) is placed at a distance of \(15~\text{cm}\) from the pole \(P\) as shown. The distance of the final image of \(O\) from \(P\) as viewed from the left is:
| 1. | \(20~\text{cm}\) | 2. | \(30~\text{cm}\) |
| 3. | \(40~\text{cm}\) | 4. | \(50~\text{cm}\) |
| 1. | \(45\) cm | 2. | \(30\) cm |
| 3. | \(15\) cm | 4. | \(25\) cm |
| 1. | \(4.5\text{cm}\) | 2. | \(20.0\text{cm}\) |
| 3. | \(9.37\text{cm}\) | 4. | \(6.67\text{cm}\) |
1. \(2\)
2. \(1.5\)
3. \(1.75\)
4. \(1.3\)
A mark on the surface of the sphere \(\left(\mu= \frac{3}{2}\right)\) is viewed from a diametrically opposite position. It appears to be at a distance \(15~\text{cm}\) from its actual position. The radius of the sphere is:
1. \(15~\text{cm}\)
2. \(5~\text{cm}\)
3. \(7.5~\text{cm}\)
4. \(2.5~\text{cm}\)
| 1. | less than \(\dfrac x4\) |
| 2. | more than \(\dfrac x4\) but less than \(\dfrac x2\) |
| 3. | \(\dfrac x2\) |
| 4. | \(\dfrac x4\) |
| 1. | \(8~\text{cm}\) inside the sphere | 2. | \(12~\text{cm}\) inside the sphere |
| 3. | \(4~\text{cm}\) inside the sphere | 4. | \(3~\text{cm}\) inside the sphere |
- 1(current)
Q. No.
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