Q. The electron in the hydrogen atom jumps from excited state $(n = 3)$ to its ground state $(n = 1)$ and the photons thus emitted irradiate a photosensitive material. If the work function of the material is $5.1\ eV$, the stopping potential is estimated to be (the energy of the electron in $n^{th}$ state $E_{n} = - \frac{13.6}{n^{2}}eV$)
A) 5.1 V
B) 12.1 V
C) 17.2 V
D) 7 V
Explanation
(d) $V = (12.1 - 5.1)volt$
$V_{stopping} = 7V$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.