1. | they travel with the speed of sound. |
2. | the frequency is not constant. |
3. | they can, heavily absorbed by the atmosphere. |
4. | the height of antenna has to be increased several times. |
A | B | Y |
0 | 0 | 1 |
0 | 1 | 1 |
1 | 0 | 1 |
1 | 1 | 0 |
1. \(0.01\) m
2. \(0.02\) m
3. \(0.05\) m
4. \(0.03\) m
\(y=3\sin\pi\Big(\frac t2-\frac x4\Big),\) represents an equation of a progressive wave, where \(t\) is in second and \(x\) is in meter. The distance travelled by the wave in \(5\) seconds is:
1. \(8\) m
2. \(10\) m
3. \(5\) m
4. \(32\) m
A body of mass \(m_1=4~\mathrm{kg}\) moves at \(5i~\mathrm{m/s}\) and another body of mass \(m_2=2~\mathrm{kg}\) moves at \(10i~\mathrm{m/s}\). The kinetic energy of the centre of mass is:
1. \(\frac{200}{3}~\text J\)
2. \(\frac{500}{3}~\text J\)
3. \(\frac{400}{3}~\text J\)
4. \(\frac{800}{3}~\text J\)
A wheel of radius \(0.4~\mathrm{m}\) can rotate freely about its axis as shown in the figure. A string is wrapped over its rim, and a mass of \(4~\mathrm{kg}\) is hung. An angular acceleration of \(8~\mathrm{rad/s^2}\) is produced in it due to the torque. Then, moment of inertia of the wheel is: (Take \(g=10\) ms-2)
1. \(2~\mathrm{kg-m^2}\)
2. \(1~\mathrm{kg-m^2}\)
3. \(4~\mathrm{kg-m^2}\)
4. \(8~\mathrm{kg-m^2}\)