Question

The minimum energy required to remove an electron is called
A. Stopping potential
B. Kinetic energy
C. Work function
D. None of these

Answer 1

Hint: In order to know about the term which is defined for the minimum energy required to remove an electron, here we will discuss each of the four given options and then will get to know which option is correct for given statement with base of Photoelectric effect.

Complete answer:
 Considering the first option (A) Stopping potential, this term is related to the photoelectric effect which is the phenomenon of emitting electrons from the atoms of a material when some sufficient amount of light energy is falling on it. So, the potential of the plates which is used to produce potential difference by photoelectric effect when the photocurrent becomes zero means no electrons emit from the material is known as stopping potential.

Now, option (B) Kinetic energy, since Kinetic energy is just defined as the energy of a body due to its motion which has a value of $K.E = \dfrac{1}{2}m{v^2}$ where m is mass and v is the velocity of the body and option (C) Work function. This term is also related with photoelectric effect as discussed in option (A), So, Work function is defined as the minimum amount of energy needed to remove an electron from the atom. So, the minimum energy required to remove an electron is called the Work function.

Hence, the correct option is C.

Note: It should be remembered that, In case of photoelectric effect, the work function, and the applied energy of the light which falls on material and the kinetic energy of the emitted electron are related by the famous equation written as $E = W + K.E$ where $E$ is total energy falls on atom, $W$ is work function and $K.E$ is Kinetic energy of emitted electron.