Light of frequency \(v\) falls on the material of threshold frequency \(v_0.\) Maximum kinetic energy of the emitted electron is proportional to:
1. \(v-v_0\)
2. \(v\)
3. \(\sqrt{v-v_0}\)
4. \(v_0\)

A light moves from denser to rarer medium, which of the following is correct?

Which one of the following statements is true?

A metro train starts from rest and in \(5\) s achieves \(108\) km/h. After that it moves with a constant velocity and comes to rest after travelling \(45\) m with uniform retardation. If total distance travelled is \(395\) m, then total time of travelling is:
1. \(12.2\) s
2. \(15.3\) s
3. \(9\) s
4. \(17.2\) s

A closed organ pipe of length \(20\) cm is sounded with a tuning fork in resonance. What is the frequency of the tuning fork? (\(v=332\) m/s)
1. \(300\) Hz
2. \(350\) Hz
3. \(375\) Hz
4. \(415\) Hz

The temperature of the sun can be found out by using:

The pressure of an ideal gas is increased by keeping temperature constant. What is the effect on the kinetic energy of molecules?

Kirchhoff’s law of junction, \(\sum I = 0,\) is based on:

A transverse wave is expressed as, \(y=y_0\sin(2\pi ft).\) For what value of \(\lambda\), maximum particle velocity equals 4 times the wave velocity?
1. \(\frac{y_0\pi}{2}\)
2. \(2y_0\pi\)
3. \(y_0\pi\)
4. \(\frac{y_0 \pi}{4}\)

For a given lens, the magnification was found to be twice as large as when the object was \(0.15\) m distant from it as when the distance was \(0.2\) m. The focal length of the lens is:
1. \(1.5~\mathrm{m}\) 
2. \(0.20\mathrm{~m}\) 
3. \(0.10~\mathrm{m}\) 
4. \(0.05~\mathrm{m}\)