Student Login

Home›Chapters›Dual Nature of Radiation and Matter PYQs›Photoelectric Effect: Einstein's Equation›Question 145

NEET 2015 (AIPMT) · Photoelectric Effect: Einstein's Equation

Photoelectric Effect: Einstein's Equation question from NEET 2015 (AIPMT)

Q145NEET 2015 · AIPMTMedium

Photoelectric Effect: Einstein's Equation

A photoelectric surface is illuminated successively by monochromatic light of wavelength $\lambda$ and $\lambda/2$ . If the maximum kinetic energy of the emitted photoelectrons in the second case is 3 times that in the first case, the work function of the surface of the material is

(h = Planck's constant, C = speed of light)

Show answer and solution

Answer: (c)

$K = \frac{hc}{\lambda} - \phi$ ; write $A = \frac{hc}{\lambda}$ .
First: $K_1 = A - \phi$ ; second ( $\lambda/2$ ): $K_2 = 2A - \phi$
$2A - \phi = 3(A - \phi) \Rightarrow 2\phi = A$
So the answer is (c) $\phi = \frac{hc}{2\lambda}$ .

Report a mistake

More questions on Photoelectric Effect: Einstein's Equation

A certain metallic surface is illuminated with monochromatic light of wavelength, λ. The…NEET 2015 (AIPMT, Cancelled Paper)
Light of wavelength 500 nm is incident on a metal with work function 2.28 eV. The de…NEET 2015 (AIPMT)
When the energy of the incident radiation is increased nby 20%, the kinetic energy of the…NEET 2014 (AIPMT)
For photoelectric emission from certain metal the cutoff frequency is v. If radiation of…NEET 2013
A copper ball of radius 1 cm and work function 4.47 eV is irradiated with ultraviolet…JEE Main 2013 (25 Apr, Shift 1)
Two radiations of photons energies 1 eV and 2.5 eV, successively illuminate a…NEET 2012 (AIPMT, Mains)
Monochromatic radiation emitted when electron on hydrogen atom jumps from first excited…NEET 2012 (AIPMT, Prelims)
Photoelectric emission occurs only when the incident light has more than a certain minimumNEET 2011 (AIPMT, Prelims)