The work functions for potassium and cesium are \(2.25 eV\) and \(2.14 eV\) respectively. Is the photoelectric effect possible for either of them if the incident wavelength is 5180 ?
[Given : Planck's constant \(=6.63 \times 10^{-34} J . s\); Velocity of light \(=3 \times 10^8 m / s ; 1 eV =1.6 \times 10^{-19} J\) ]

State Einstein's photoelectric equation. Explain two characteristic of photoelectric effect on the basis of Einstein photoelectron equation.

Light of wavelength 3000Å falls on a metal surface having work function \(2.3 eV\). Calculate the maximum velocity of ejected electrons. (Planck's constant \(h=6.63 \times 10^{34}\) J.s., Velocity of light \(c=3 \times 10^8 m / s\), Mass of an electron \(=9.1 \times 10^{-31} kg\) )

What is de-Broglie hypothesis? Obtain the relation for de-Broglie wavelength.

The photoelectric current in a photoelectric cell can be reduced to zero by a stopping potential of 1.8 volt. Monochromatic light of wavelength 2200Å is incident on the cathode. Find the maximum kinetic energy of the photoelectrons in joules. [Charge on electron \(=1.6 \times 10^{-19} C\)]

What is photoelectric effect? Define: (i) Stopping potential, (ii) Photoelectric work function.

State Einstein's photoelectric equation. Explain any two characteristics of photoelectric effect on the basis of this equation.

The photoelectric work function for a metal is \(4.2 eV\). If the stopping potential is \(3 V\), find the threshold wavelength and maximum kinetic energy of emitted electrons. (Velocity of light in air \(=3 \times 10^8 m / s\),) Planck's constant \(=6.63 \times 10^{-34} J - s\), Charge on electron \(=1.6 \times 10^{-19} C\) )

The work function for a metal surface is \(2.2 eV\). If light of wavelength 5000Å is incident on the surface of the metal, find the threshold frequency and incident frequency. Will there be an emission of photoelectrons or not? \(\left(c=3 \times 10^8 m / s , 1 eV =1.6 \times 10^{-19} J , h =6.63 \times 10^{-34} J . s\right.\). \()\)

Draw a well labelled diagram of photoelectric cell. Explain the observations made by Hertz and Lenard about the phenomenon of photoelectric emission.