The stopping potential does not depend on the intensity of incident radiation; so stopping potential will remain unchanged.

No, most electrons get scattered into the metal. Only a few come out of the surface of the metal.

The amount of light energy or photon energy incident per meter square per second is called the intensity of radiation.
SI unit: \(\frac { W }{ { m }^{ 2 } } \) or J/s-m².

"Photoelectric effect" shows the quantum nature of electromagnetic radiation.

Maximum kinetic energy, (E_k)_max = eVs = e(2V) = 2eV

(i) The photoelectric current increases proportionally with the increase in intensive of incident radiation.
(ii) Larger the intensity of incident radiation, larger is the number of incident photons and hence larger is the number of electrons ejected from the photosensitive surface.

The minimum retarding (negative) potential of anode of a photoelectric tube fro which photoelectric current stops or becomes zero is called the stopping potential.

A photon is a bundle of energy of electromagnetic wave. For a frequency of wave v, energy of a photon E = hv.

In photoelectric effect, a single photon interacts with a single electron. As individual photo has energy (2.5 eV) which is less than work function, hence emission of electron will not take place.

According to de Broglie's hypothesis, all matter particles like electrons, protons, neutrons in motion are associated with waves. These waves are called de Broglie waves or matter waves.

The resistance of the semiconductor changes in accordance with the radiant energy incident on it.

Sensitive element made of semiconductor is used which generates voltage proportional to the intensity of light or other radiations.

Its working depends on the electron emission from a metal cathode due to irradiation of light or other radiations.

(i) Metals like cadmium, zinc, magnesium, alkali metals lithium, sodium, caesium respond to visible light.
(ii) The materials which eject photoelectrons upon irradiation of electromagnetic wave of suitable wavelength are called photosensitive materials.

The potential barrier which prevents free electrons from leaving the metallic surface is called surface barrier.