(a) | the distance between the objective and the eyepiece is \(20.02\) m. |
(b) | the magnification of the telescope is \(-1000\). |
(c) | the image of the planet is erect and diminished. |
(d) | the aperture of the eyepiece is smaller than that of the objective. |
1. | (a), (b), and (c) | 2. | (b), (c), and (d) |
3. | (c), (d), and (a) | 4. | (a), (b), and (d) |
1. | the scattering of light. |
2. | the polarisation of light. |
3. | the colour of the sun. |
4. | the colour of the sky. |
1. | \(-3\hat i+4\hat j+2\hat k\) | 2. | \(3\hat i-4\hat j-2\hat k\) |
3. | \(-3\hat i-4\hat j+2\hat k\) | 4. | \(-3\hat i+4\hat j-2\hat k\) |
A beam of light is incident vertically on a glass slab of thickness \(1\) cm, and refractive index \(1.5.\) A fraction \(A\) is reflected from the front surface while another fraction \(B\) enters the slab and emerges after reflection from the back surface. The time delay between them is:
1. | \(10^{-10}\) s | 2. | \(5\times 10^{-10}\) s |
3. | \(10^{-11}\) s | 4. | \(5\times 10^{-11}\) s |
A concave lens of focal length \(-25\) cm is sandwiched between two convex lenses, each of focal length, \(40\) cm. The power in dioptre of the combined lens would be:
1. | \(55\) | 2. | \(9\) |
3. | \(1\) | 4. | \(0.01\) |
1. | \(120^\circ\) | 2. | \(30^\circ\) |
3. | \(60^\circ\) | 4. | \(90^\circ\) |
1. | infinity | 2. | \(+2~\text{D}\) |
3. | \(+20 ~\text{D}\) | 4. | \(+5~\text{D}\) |