In Young's double-slit experiment, the intensity of light at a point on the screen where the path difference is \(\lambda\) is \(K\), (\(\lambda\) being the wavelength of light used). The intensity at a point where the path difference is \(\frac{\lambda}{4}\) will be:
1. \(K\)
2. \(\frac{K}{4}\)
3. \(\frac{K}{2}\)
4. zero
If the focal length of the objective lens is increased then the magnifying power of:
| 1. | microscope will increase but that of the telescope decrease. |
| 2. | microscope and telescope both will increase. |
| 3. | microscope and telescope both will decrease. |
| 4. | microscope will decrease but that of the telescope will increase. |
The angle of a prism is \(A\). One of its refracting surfaces is silvered. Light rays falling at an angle of incidence \(2{A}\) on the first surface return back through the same path after suffering reflection at the silvered surface. The refractive index \(\mu,\) of the prism, is:
1. \(2\text{sin}A\)
2. \(2\text{cos}A\)
3. \(\dfrac{1}{2}\text{cos}A\)
4. \(\text{tan}A\)
| 1. | \(0.65~\text{eV}\) | 2. | \(1.0~\text{eV}\) |
| 3. | \(1.3~\text{eV}\) | 4. | \(1.5~\text{eV}\) |
If the kinetic energy of the particle is increased to \(16\) times its previous value, the percentage change in the de-Broglie wavelength of the particle is:
| 1. | \(25\) | 2. | \(75\) |
| 3. | \(60\) | 4. | \(50\) |
The hydrogen gas with its atoms in the ground state is excited by monochromatic radiation of \(\lambda = 975~\mathring{{A}}.\) The number of spectral lines in the resulting spectrum emitted will be:
1. \(3\)
2. \(2\)
3. \(6\)
4. \(10\)
The Binding energy per nucleon of \(^{7}_{3}\mathrm{Li}\) and \(^{4}_{2}\mathrm{He}\) nucleon are \(5.60~\text{MeV}\) and \(7.06~\text{MeV}\), respectively. In the nuclear reaction \(^{7}_{3}\mathrm{Li} + ^{1}_{1}\mathrm{H} \rightarrow ^{4}_{2}\mathrm{He} + ^{4}_{2}\mathrm{He} +Q\), the value of energy \(Q\) released is:
| 1. | \(19.6~\text{MeV}\) | 2. | \(-2.4~\text{MeV}\) |
| 3. | \(8.4~\text{MeV}\) | 4. | \(17.3~\text{MeV}\) |
A radioisotope 'X' with a half-life 1.4 × 109 years decays to 'Y' which is stable. A sample of the rock from a cave was found to contain 'X' and 'Y' in the ratio 1:7. The age of the rock is:
1. 1.96 x 109 years
2. 3.92 x 109 years
3. 4.20 x 109 years
4. 8.40 x 109 years
The given graph represents the \(\mathrm{V\text{-} I}\) characteristic for a semiconductor device.
Which of the following statement is correct?
| 1. | It is a \(\mathrm{V\text{-} I}\) characteristic for the solar cell where point \(\mathrm{A}\) represents open-circuit voltage and point \(\mathrm{B}\) short circuit current. |
| 2. | It is for a solar cell and points \(\mathrm{A}\) and \(\mathrm{B}\) represent open-circuit voltage and current, respectively. |
| 3. | It is for a photodiode and points \(\mathrm{A}\) and \(\mathrm{B}\) represent open-circuit voltage and current respectively. |
| 4. | It is for a LED and points \(\mathrm{A}\) and \(\mathrm{B}\) represent open circuit voltage and short circuit current, respectively. |
| (a) | type of semiconductor material |
| (b) | amount of doping |
| (c) | temperature |
Which one of the following is correct?
| 1. | (a) and (b) only | 2. | (b) only |
| 3. | (b) and (c) only | 4. | (a), (b) and (c) |