Modern Physics PHY 36001

Question 1.

A black body is an object that perfectly absorbs all incident radiation on its surface.

       True
       False

Question 2.

In pair production a photon has all its energy converted into a pair of electrons.

       True
       False

Question 3.

Planck argued that the energy of the radiation inside a cavity could only be emitted and absorbed in discrete bundles, he called quanta.

       True
       False

Question 4.

The energy of each quantum of light is given by E = h c, where h is Plancks constant and c is the speed of light.

       True
       False

Question 5.

Bremmstrahlung is the release of light when an electron is slowed down by its interactions with some medium.

       True
       False

Question 1.

In electron-positron creation, which of these quantities are conserved?

      a. energy
      b. momentum
      c. charge
      d. all of the above
      e. just energy and momentum.

Question 2.

Photons are particle-like quanta (or bundles) of light with which of the following properties

      a. like other particles, they move at less than speed of light.
      b. they always have a mass.
      c. they have no rest mass and hence carry no momentum p.
      d. they can be created and destroyed.

Question 3.

According to the delay choice experiment, we find that

      a. light emitted from one source behaves either like a wave or a particle but not both. Which one depends on the light source used.
      b. light emitted from one source will naturally behave like a wave, but when the beam is blocked by a switch then the light behaves like a particle.
      c. light is comprised of particles (photons) and its wave-like nature comes from the fact that light has many photons in it, just like the way water molecules comprise waves in the ocean.
      d. light has a dual nature. Its apparent wave-like or particle-like nature depends on which aspect you choose to measure. It's like wave-particle duality, Yin-Yang and all that, man!