What is a photo cell? Mention the different types of photocells.

Name an experiment that shows the wave nature of the electron. Which phenomenon was observed in this experiment using an electron beam?

List out the laws of photo electric effect.

A 150 W lamp emits light of mean wavelength of 5500 Å. If the efficiency is 12%, find out the number of photons emitted by the lamp in one second.

How many photons of frequency 10¹⁴ Hz will make up 19.86 J of energy?

What should be the velocity of the electron so that its momentum equals that of 4000 Å wavelength photon.

When a light of frequency 9 x 10¹⁴ Hz is incident on a metal surface, photoelectrons are emitted with a maximum speed of 8 x 10⁵ m/s. Determine the threshold frequency of the surface.

When a 6000Å light falls on the cathode of a photo cell, photoemission takes place. If a potential of 0.8 V is required to stop emission of electron, then determine the
(i) frequency of the light
(ii) energy of the incident photon
(iii) work function of the cathode material
(iv) threshold frequency and
(v) net energy of the electron after it leaves the surface.

UV light of wavelength 1800 Å is incident on a lithium surface whose threshold wavelength is 4965 Å. Determine the maximum energy of the electron emitted.

Calculate the de Broglie wavelength of a proton whose kinetic energy is equal to 81.9 x 10^–15 J. (Given: mass of proton is 1836 times that of electron).

A deutron and an alpha particle alpha particle are accelerated with the same potential. Which one of the two has
i) greater value of de Broglie wavelength associated with it and
ii) less kinetic energy? Explain.

An electron is accelerated through a potential difference of 81V. What is the de Broglie wavelength associated with it? To which part of electromagnetic spectrum does this wavelength correspond?

The ratio between the de Broglie wavelength associated with proton, accelerated through a potential of 512 V and that of alpha particle accelerated through a potential of X volts is found to be one. Find the value of X.

The work function of potassium is 2.30 eV. UV light of wavelength 3000 Å and intensity 2 Wm^–2 is incident on the potassium surface.
i) Determine the maximum kinetic energy of the photo electrons
ii) If 40% of incident photons produce photo electrons, how many electrons are emitted per second if the area of the potassium surface is 2 cm²?

Light of wavelength 390 nm is directed at a metal electrode. To find the energy of electrons ejected, an opposing potential difference is established between it and another electrode. The current of photoelectrons from one to the other is stopped completely when the potential difference is 1.10 V. Determine i) the work function of the metal and ii) the maximum wavelength of light that can eject electrons from this metal.

Calculate the momentum and the de Broglie wavelength in the following cases:
i) an electron with kinetic energy 2 eV.
ii) a bullet of 50 g fired from rifle with a speed of 200 m/s
iii) a 4000 kg car moving along the highways at 50 m/s
Hence show that the wave nature of matter is important at the atomic level but is not really relevant at macroscopic level.

Find the de Broglie wavelength associated with an alpha particle which is accelerated through a potential difference of 400 V. Given that the mass of the proton is 1.67 x 10^–27 kg.

A proton and an electron have same de Broglie wavelength. Which of them moves faster and which possesses more kinetic energy?

Write the expression for the de Broglie wavelength associated with a charged particle of charge q and mass m, when it is accelerated through a potential V.