Out of the following options which one can be used to produce a propagating electromagnetic wave?
| 1. | a stationary charge. |
| 2. | a chargeless particle. |
| 3. | an accelerating charge. |
| 4. | a charge moving at constant velocity. |
| 1. | \(\dfrac{a^3R}{3b}\) | 2. | \(\dfrac{a^3R}{2b}\) |
| 3. | \(\dfrac{a^3R}{b}\) | 4. | \(\dfrac{a^3R}{6b}\) |
| 1. | \(\alpha_1L_2^2=\alpha_2L_1^2\) | 2. | \(\alpha_1^2L_2=\alpha_2^2L_1\) |
| 3. | \(\alpha_1L_1=\alpha_2L_2\) | 4. | \(\alpha_1L_2=\alpha_2L_1\) |
The intensity at the maximum in Young's double-slit experiment is \(I_0\). The distance between the two slits is \(d= 5\lambda\), where \(\lambda \) is the wavelength of light used in the experiment. What will be the intensity in front of one of the slits on the screen placed at a distance \(D = 10 d\)?
| 1. | \(\dfrac{I_0}{4}\) | 2. | \(\dfrac{3}{4}I_0\) |
| 3. | \(\dfrac{I_0}{2}\) | 4. | \(I_0\) |
A car is negotiating a curved road of radius \(R\). The road is banked at an angle \(\theta\). The coefficient of friction between the tyre of the car and the road is \(\mu_s\). The maximum safe velocity on this road is:
| 1. | \(\sqrt{\operatorname{gR}\left(\dfrac{\mu_{\mathrm{s}}+\tan \theta}{1-\mu_{\mathrm{s}} \tan \theta}\right)}\) | 2. | \(\sqrt{\frac{\mathrm{g}}{\mathrm{R}}\left(\dfrac{\mu_{\mathrm{s}}+\tan \theta}{1-\mu_{\mathrm{s}} \tan \theta}\right)}\) |
| 3. | \(\sqrt{\frac{\mathrm{g}}{\mathrm{R}^2}\left(\dfrac{\mu_{\mathrm{s}}+\tan \theta}{1-\mu_{\operatorname{s}} \tan \theta}\right)}\) | 4. | \(\sqrt{\mathrm{gR}^2\left(\dfrac{\mu_{\mathrm{s}}+\tan \theta}{1-\mu_{\mathrm{s}} \tan \theta}\right)}\) |
| 1. | paramagnetic material only. |
| 2. | ferromagnetic material only. |
| 3. | paramagnetic and ferromagnetic materials. |
| 4. | diamagnetic material only. |