A siren emitting a sound of frequency \(800\) Hz moves away from an observer towards a cliff at a speed of \(15\) ms-1. Then, the frequency of sound that the observer hears in the echo reflected from the cliff is:
(Take, the velocity of sound in air = \(330\) ms-1)
1. \(800\) Hz
2. \(838\) Hz
3. \(885\) Hz
4. \(765\) Hz
| 1. | \(\left(2 t^2+4 t^4\right)\text W\) | 2. | \(\left(2 t^3+3 t^3\right) \text W \) |
| 3. | \(\left(2 t^3+3 t^5\right) \text W\) | 4. | \(\left(2 t^3+3 t^4\right) \text W\) |
| 1. | \(\dfrac{13}{32}MR^2\) | 2. | \(\dfrac{11}{32}MR^2\) |
| 3. | \(\dfrac{9}{32}MR^2\) | 4. | \(\dfrac{15}{32}MR^2\) |
If a square loop \({ABCD}\) carrying a current \(i\) is placed near and coplanar with a long straight conductor \({XY}\) carrying a current \(I,\) what will be the net force on the loop?

| 1. | \(\dfrac{\mu_0Ii}{2\pi}\) | 2. | \(\dfrac{2\mu_0IiL}{3\pi}\) |
| 3. | \(\dfrac{\mu_0IiL}{2\pi}\) | 4. | \(\dfrac{2\mu_0Ii}{3\pi}\) |
| 1. | \(100~\text{cm}\) | 2. | \(150~\text{cm}\) |
| 3. | \(200~\text{cm}\) | 4. | \(66.7~\text{cm}\) |
| 1. | \(\dfrac{400}{\sqrt{3}}\) | 2. | \(\dfrac{100\sqrt{2}}{3}\) |
| 3. | \(\dfrac{100}{3}\) | 4. | \(100\sqrt{2}\) |
Consider the junction diode as an ideal. The value of current flowing through \(AB\) is:
1. \(10^{-2}~\text{A}\)
2. \(10^{-1}~\text{A}\)
3. \(10^{-3}~\text{A}\)
4. \(0~\text{A}\)