GATE Physics Practice Quiz

Question 1

For a hydrogen-like ion of nuclear charge Z, the wavelength of the Lyman-α line corresponds to the transition n=2 to n=1. If the Lyman-α wavelength in hydrogen is λ_H, the corresponding wavelength for He+ is

Accepted Answer

λ_H/4

Question 2

In LS coupling, consider a term with L=1 and S=1. Which value of J is NOT allowed?

Accepted Answer

J=3

Question 3

For the sodium D-lines arising from the 3p state split by spin-orbit interaction, the two upper levels are 3p 2P1/2 and 3p 2P3/2. Using the Landé interval rule for a 2P term, the energy separation satisfies

Accepted Answer

E(2P3/2)-E(2P1/2)=3A/2

Question 4

A non-degenerate atomic level has no permanent electric dipole moment. In a weak static electric field, the first-order Stark shift of this level is

Accepted Answer

zero, while the leading nonzero shift is second order in the field

Question 5

Which of the following electric dipole transitions in a one-electron atom is allowed?

Accepted Answer

2p → 1s

Quizzes