From Einstein's photoelectric equation, hν=ϕ+eV0.
⇒V0=ehν−eϕ......(1)
At ν=4×1014Hz, V0=0.
Putting the value in equation (1), we get
0=ehv−eϕ
So, Work function (ϕ)=e(hν)(ineV)
=1.6×10−196.63×10−34×(4×1014)
=1.66eV
JEE Main 2019 — Physics Modern Physics
2019mcqeasy
The stopping potential Vo (in volt) as a function of frequency (v) for a sodium emitter, is shown in the figure. The work function of sodium, form the data plotted in the figure, will be:
(Given: Planck’s constant (h)=6.63×10−34Js , electron charge (e) =1.6×10−19C)
Official previous-year question
Held on 12 Apr 2019 · Verified 6 Jul 2026.
Options
- A
2.12eV
- B
1.82eV
- C
1.95eV
- D
1.66eV
Did you get this right?
Sign in to track your attempts and accuracy.
Your note
Sign in to keep a private note on this question. Nothing you write is ever public.
JEE Main Modern Physics in other years
More JEE Main Modern Physics questions
A voltage regulating circuit consisting of Zener diode, having break-down voltage of 10 V and maximum power dissipation of 0.4 W, is operated at 15 V. The approximate value of protective resistance in this circuit is $\_\_\_\_$ $\Omega$.
2026medium
An atom ${ }_{3}^{8} X$ is bombarded by shower of fundamental particles and in 10 s this atom absorbed 10 electrons, 10 protons and 9 neutrons. The percentage growth in the surface area of the nucleons is recorded by:
2026hard
In the hydrogen atom, the electron makes a transition from the higher orbit ($i$) to a lower orbit ($f$). The ratio of the radius of the orbits in given by $r_i : r_f = 16 : 4$. The wavelength of photon emitted due to this transition is _____ nm. (Given Rydberg constant $= 1.0973 \times 10^7$ /m)
2026medium
The work function of a metal is 4.2 eV. The threshold wavelength for photoelectric emission is approximately:
2026medium
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): The electromagnetic wave exerts pressure on the surface on which they are allowed to fall. Reason (R): There is no mass associated with the electromagnetic waves. In the light of the above statements, choose the correct answer from the options given below :
2026medium
Other Physics topics for JEE Main
Keep practicing Modern Physics
Work through every JEE Main Modern Physics PYQ, year by year.