The work function of cesium is \(2.14 ~\text{eV}.\) The threshold frequency for cesium is:

1.	\(5.03\times10^{12}~\text{Hz}\)	2.	\(6.12\times10^{14}~\text{Hz}\)
3.	\(5.16\times10^{14}~\text{Hz}\)	4.	\(6.51\times10^{12}~\text{Hz}\)

The work function of caesium is \(2.14~\text{eV}\). The wavelength of incident light if the photocurrent is brought to zero by a stopping potential of \(0.60~\text{V}\) will be:
1. \(454~\text{nm}\)
2. \(440~\text{nm}\)
3. \(333~\text{nm}\)
4. \(350~\text{nm}\)

What is the de-Broglie wavelength associated with an electron moving at a speed of \(5.4\times10^6~\text{m/s}\)?

The wavelength of light in the visible region is about \(550~\text{nm}\) (average wavelength) for yellow-green colour. Three materials with work functions are given as \(Al~(4.28~\text{eV}),\) \(Cu~(4.65~\text{eV})\) and \(Na~(2.75~\text{eV}).\) From which of these photosensitive materials can you build a photoelectric device that operates with visible light?
1. \(Al\)
2. \(Cu\)
3. \(Na\)
4. none of the above

A photo-cell is illuminated by a source of light, which is placed at a distance \(d\) from the cell. If the distance becomes \(\dfrac{d}{2}\), then the number of electrons emitted per second will be: 
1. same
2. four times
3. two times
4. one-fourth

Which of the following is not the property of cathode rays?

According to Einstein's photoelectric equation, the graph between the kinetic energy of photoelectrons ejected and the frequency of incident radiation is:

1.		2.
3.		4.

Two photons have: