What is the bremsstrahlung process? A. The emission of a photon ...

[go.lag]

What is the bremsstrahlung process?
  A. The emission of a photon from an electron being accelerated by a nucleus
  B. The emission of an electron from a metal when light is shined on it
  C. Thermal excitation of photons in a substance
  D. The emission of an electron from an inner electron shell and the resulting photon when an electron drops from an outer shell to take its place
  E. Converting power-producing nuclear material to weapons grade

Question 2

An electron approaches a positron. They annihilate and produce two photons, which fly off at the speed of light in opposite directions. Analyze the situation using relativistic momentum and energy and choose the false statement below.
 

A. If the resulting photons have the same wavelength, then the electron and positron must have had equal momenta.
  B. The kinetic energies of the positron and electron determine the frequency of the gamma rays produced in the annihilation.
  C. The rest energies of the positron and electron determine the frequency of the gamma rays produced in the annihilation.
  D. The photons can have the same wavelength, but it is not necessary.
  E. There can be two photons produced (as in the above example), but only one photon can is produced in some cases.

[lauravaras]

Answer to Question 1

A.
When an electron passes significantly close to a nucleus, the electron enters a relatively strong electric field. The electron accelerates (that is, changes speed and/or direction) in the field and emits a photon because all accelerating electrons emit photons.

Answer to Question 2

E.
This statement is false because two photons must be produced to conserve linear momentum. One photon cannot possibly conserve linear momentum because of the rest and kinetic energies associated with the positron-electron pair as well as the directions of travel.