A body of mass \(1\) kg is thrown upwards with a velocity \(20\) ms-1. It momentarily comes to rest after attaining a height of \(18\) m. How much energy is lost due to air friction?
(Take \(g=10\) ms-2)
1. \(20\) J
2. \(30\) J
3. \(40\) J
4. \(10\) J
The symbolic representation of four logic gates is as shown:
| (i) | (ii) | ||
| (ii) | (iv) |
The logic symbols for OR, NOT, and NAND gates are respectively:
1. (iii), (iv), (ii)
2. (iv), (i), (iii)
3. (iv), (ii), (i)
4. (i), (iii), (iv)
If \(\vec F\) is the force acting on a particle having position vector \(\vec r\) and \(\vec \tau\) be the torque of this force about the origin, then:
| 1. | \(\vec r\cdot\vec \tau\neq0\text{ and }\vec F\cdot\vec \tau=0\) |
| 2. | \(\vec r\cdot\vec \tau>0\text{ and }\vec F\cdot\vec \tau<0\) |
| 3. | \(\vec r\cdot\vec \tau=0\text{ and }\vec F\cdot\vec \tau=0\) |
| 4. | \(\vec r\cdot\vec \tau=0\text{ and }\vec F\cdot\vec \tau\neq0\) |
If a diamagnetic substance is brought near the north or the south pole of a bar magnet, it is:
| 1. | repelled by both the poles |
| 2. | repelled by the north pole and attracted by the south pole |
| 3. | attracted by the north pole and repelled by the south pole |
| 4. | attracted by both the poles |
The mass of a lift is \(2000\) kg. When the tension in the supporting cable is \(28000\) N, then its acceleration is:
(Take \(g=10\) m/s2)
| 1. | \(30\) ms-2 downwards | 2. | \(4\) ms-2 upwards |
| 3. | \(4\) ms-2 downwards | 4. | \(14\) ms-2 upwards |
The number of beta particles emitted by a radioactive substance is twice the number of alpha particles emitted by it. The resulting daughter is an:
| 1. | isobar of a parent. | 2. | isomer of a parent. |
| 3. | isotone of a parent. | 4. | isotope of a parent. |
| 1. | the rectangular, circular, and elliptical loops. |
| 2. | the circular and the elliptical loops. |
| 3. | only the elliptical loop. |
| 4. | any of the four loops. |
A particle starts its motion from rest under the action of a constant force. If the distance covered in the first \(10\) s is \(S_1\) and that covered in the first \(20\) s is \(S_2\), then:
1. \(S_2=2S_1\)
2. \(S_2 = 3S_1\)
3. \(S_2 = 4S_1\)
4. \(S_2= S_1\)
A wire of resistance \(12~ \Omega \text{m}^{-1}\) is bent to form a complete circle of radius \(10~\text{cm}\). The resistance between its two diametrically opposite points, \(A\) and \(B\) as shown in the figure, is:
| 1. | \(0.6\pi~\Omega\) | 2. | \(3\pi ~\Omega\) |
| 3. | \(61 \pi~ \Omega\) | 4. | \(6\pi~\Omega\) |
| 1. | Moving along y-direction with frequency 21 π x 106 Hz and wavelength 200 m. |
| 2. | Moving along x-direction with frequency 106 Hz and wavelength 100m |
| 3. | Moving along x-direction with frequency 106 Hz and wavelength 200m |
| 4. | Moving along x-direction with frequency 106 Hz and wavelength 800m |