A body is moving with a velocity of \(30~\text{m/s}\) towards the east. After \(10~\text s,\) its velocity becomes \(40~\text{m/s}\) towards the north. The average acceleration of the body is:
1. \( 7~\text{m/s}^2\)
2. \( \sqrt{7}~\text{m/s}^2\)
3. \(5~\text{m/s}^2\)
4. \(1~\text{m/s}^2\)
| 1. | virtual, upright, height \(=0.5\) cm |
| 2. | real, inverted, height \(=4\) cm |
| 3. | real, inverted, height \(=1\) cm |
| 4. | virtual, upright, height \(=1\) cm |
| 1. | Difference between apparent and real depth of the pond |
| 2. | Mirage on hot summer days |
| 3. | Brilliance of the diamond |
| 4. | Working of optical fibre |
The potential energy of a system increases if work is done:
| 1. | by the system against a conservative force |
| 2. | by the system against a non-conservative force |
| 3. | upon the system by a conservative force |
| 4. | upon the system by a non-conservative force |
| 1. | the positive terminal of the battery is connected to the p-side and the depletion region becomes thick. |
| 2. | the negative terminal of the battery is connected to the n-side and the depletion region becomes thin. |
| 3. | the positive terminal of the battery is connected to the n-side and the depletion region becomes thin. |
| 4. | the negative terminal of the battery is connected to the p-side and the depletion region becomes thick. |
A missile is fired for a maximum range with an initial velocity of \(20~\text {m/s}.\) If \(g=10~\text{m/s}^2,\) then the range of the missile will be:
| 1. | \(50~\text m\) | 2. | \(60~\text m\) |
| 3. | \(20~\text m\) | 4. | \(40~\text m\) |
The current \(i\) in a coil varies with time as shown in the figure. The variation of induced emf with time would be:
| 1. | 2. | ||
| 3. | 4. |
An AC voltage is applied to a resistance R and an inductor L in series. If R and the inductive reactance are both equal to 3 , the phase difference between the applied voltage and the current in the circuit is:
1.
2.
3. zero
4.