AIPMT PRELIMS2005Physics-Photoelectric Effect

AIPMT PRELIMS 2005 Physics Work Function and Threshold Frequency MCQ Question

Type: MCQ-numerical-Medium-Class 12

The work functions for metals A, B and C are respectively 1.92 eV, 2.0 eV and 5 eV. According to Einstein's equation, the metals which will emit photoelectrons for a radiation of wavelength 4100 Å is/are:

A

none

B

A only

C

A and B only

D

all the three metals

Correct Answer

Option C

Detailed Explanation

The energy of the incident photon is given by E=hcλE = \frac{hc}{\lambda}. For λ=4100\lambda = 4100 Å, the energy is approximately 3.02 eV. Metals A and B have work functions less than this energy, so they will emit photoelectrons.

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