Question

The time taken by a photoelectron in order to come out after the photon will be striking is approximately,
$\begin{align}
  & A{{.10}^{-1}}s \\
 & B{{.10}^{-2}}s \\
 & C{{.10}^{-10}}s \\
 & D{{.10}^{-16}}s \\
\end{align}$

Answer 1

Hint: Photoelectric effect can be defined as the process in which an electrically charged substance is ejected from or within a substance if it will be absorbing the electromagnetic radiation. The effect will be sometimes explained as the ejection of the electrons from a metal plate if the light is falling on it. This will help you in answering this question.

Complete answer:
Photoelectric effect can be defined as the phenomenon in which an electrically charged material is released from or within a material if it will be absorbing the electromagnetic radiation. The effect will be sometimes explained as the ejection of the electrons from a metal plate if the light is falling on it. When a light of high energy falls on to a metal, the electrons will get emitted from the metal. The light below a particular threshold frequency will not result in any electrons to be ejected. Light above the threshold frequency, even if it will not be very intense, will be always resulting in the emission of the electrons. The emission of the photoelectron begins from the surface after the incidence of photons in about ${{10}^{-10}}s$.

The correct answer has been obtained as option C.

Note:
The explanation for the photoelectric effect goes as it takes a specific energy in order to eject an electron from the metal surface. This energy can be referred to as the work function which will be dependent on the metal. Electrons will be gaining energy by the interaction of the electrons with photons. When a photon will be having an energy which is just above the work function, the energy of the photon can be transferred to the electron and the electron must be having the required energy in order to escape from the metal. A photon which is having an energy less than the work function will never be able to emit the electrons.