AP EAMCET2013PhysicsDual Nature of Matter
The work function of a metal is 2 eV . If a radiation of wavelength 3000 Ã… is incident on it, the maximum kinetic energy of the emitted photoelectrons is (Planck's constant h=6.6 10⁻³⁴ Js ; velocity of light .c=3 10^8 ~m / s ; 1 eV =1.6 10⁻¹⁹ ~J )
Options
- A4.4 10⁻¹⁹ ~J
- B5.6 10⁻¹⁹ ~J
- C3.4 10⁻¹⁹ ~J
- D2.5 10⁻¹⁹ ~J
Correct answer
C. 3.4 10⁻¹⁹ ~J
Step-by-step solution
Maximum KE = h c - ₀ Given, =3000 Ã…=3000 10⁻¹⁰ ~m , h=6.6 10⁻³⁴ ~J - s , C =3 10^8 ~m / s , =2 eV Maximum KE aligned = & 6.6 10⁻³⁴ 3 10^8 3000 10⁻¹⁰ 1 1.6 10⁻¹² -2 = & 4.13-2=2.13 eV aligned In Joules : 2.13 1.6 10⁻¹⁹=3.41 10⁻¹⁹ ~J