Question

Choose the right answers

a)What is responsible for the production of x ray emission at the cutoff wavelength?
1)The last emission in a series of many emissions by the incident electron as it loses its energy.

2)The first emission in a series of many emissions by the incident electron as it loses its energy.

3)The most energetic emission in a series of many emissions by the incident electron as it loses its energy.

4)The least energetic emission in a series of many emissions by the incident electron as it loses its energy.

5)The emission by the incident electron when it loses its energy in a single emission

b)Which is true about the characteristic x-ray emission?

1)It is the radiation by electrons jumping up to higher energy levels.

2)It is the radiation by the incident electron in collisions with the atoms.

3)It is the radiation by electrons falling into lower energy levels.

c) Which is true about stimulated emission?

1) A photon is absorbed and then immediately re-emitted by an atom

2)A photon causes the de-excitation of an atom.

3) An atom emits two photons in opposite directions

4) A photon causes the excitation of an atom

5) An atom emits two photons in the same direction

d) Which is true about the pair of energy levels responsible for lasing?
1) The upper level is a long-lived state, said to be a metastable state.
2) The upper level is a short-lived state, said to be a metastable state

3) The lower level is a short-lived state, said to be a metastable state

Answer 1

A) ANS--When an electron loses its entire energy in a single Coulomb's interaction then X-rays of minimum wavelength (cut-off wavelength) are emitted..hence answer will be option 5

B) when any electron hit the atom then their electron gets excited in to higher orbit we know that in higher orbit an electron can not be stable ..so when it comes to lower orbit in result of this x-ray is formed...hence option 3

C) Stimulated emission is the process by which an incoming photon of a specific frequency can interact with an excited atomic electron (or other excited molecular state), causing it to drop to a lower energy leve.hence option no.2

D) option 1 is correct