Physics·Prelims Questions

Work Function — Prelims Questions

NEET UG
Updated 22 Mar 2026
Q1medium

The work function of a metal is 3.3eV3.3\,\text{eV}. What is the threshold frequency for the photoelectric emission from this metal? (Given Planck's constant h=6.6×1034,J sh = 6.6 \times 10^{-34},\text{J s} and 1eV=1.6×1019,J1\,\text{eV} = 1.6 \times 10^{-19},\text{J})

Q2medium

Light of wavelength 400nm400\,\text{nm} is incident on a metal plate. If the work function of the metal is 2.5eV2.5\,\text{eV}, what is the maximum kinetic energy of the emitted photoelectrons? (Given h=6.626×1034,J sh = 6.626 \times 10^{-34},\text{J s}, c=3×108m/sc = 3 \times 10^8\,\text{m/s}, 1eV=1.602×1019,J1\,\text{eV} = 1.602 \times 10^{-19},\text{J})

Q3easy

Which of the following statements about the work function (ϕ\phi) is INCORRECT?

Q4medium

A metal surface has a threshold wavelength of 600nm600\,\text{nm}. What is its work function in electron volts? (Given h=6.626×1034,J sh = 6.626 \times 10^{-34},\text{J s}, c=3×108m/sc = 3 \times 10^8\,\text{m/s}, 1eV=1.602×1019,J1\,\text{eV} = 1.602 \times 10^{-19},\text{J})

Q5medium

Two metals, A and B, have work functions of 2.0eV2.0\,\text{eV} and 4.0eV4.0\,\text{eV} respectively. If light of frequency 8.0×1014,Hz8.0 \times 10^{14},\text{Hz} is incident on both metals, which metal(s) will exhibit photoelectric emission? (Given h=6.6×1034,J sh = 6.6 \times 10^{-34},\text{J s}, 1eV=1.6×1019,J1\,\text{eV} = 1.6 \times 10^{-19},\text{J})

Q6easy

The work function of a metal is 4.14eV4.14\,\text{eV}. What is the threshold wavelength for this metal? (Given hc=1240eV nmhc = 1240\,\text{eV nm} for convenience)

Q7easy

If the work function of a metal is increased, what happens to its threshold frequency and threshold wavelength?