unit 4 pretest

Doping a semiconductor with impurity atoms:

• • a) Increases its conductivity.

• • b) Decreases its conductivity.

• • c) Does not affect its conductivity.

  • .

• • d) None of the above

A p-type semiconductor is formed when a pure semiconductor is doped with:

• • a) Pentavalent impurity.

• • b) Trivalent impurity.

• • c) Divalent impurity.

• • d) Monovalent impurity.

The energy gap between the valence band and the conduction band in an intrinsic semiconductor is:

• • a) Very small.

• • b) Very large.

• • c) Zero.

• • d) Depends on the temperature.

In a forward-biased p-n junction diode, the majority charge carriers move:

• • a) From p-side to n-side.

• • b) From n-side to p-side.

• • c) Both ways.

• • d) None of the above.

The process of adding impurities to a semiconductor to increase its conductivity is called (a)   .

A semiconductor doped with a pentavalent impurity is called an (a)   semiconductor.

The reverse saturation current of a diode

• • a) Increases with increasing reverse bias voltage.

• • b) Decreases with increasing reverse bias voltage.

• • c) Remains constant with increasing reverse bias voltage.

• • d) None of the above

The phenomenon of increase in conductivity of a semiconductor with increase in temperature is due to the (a)   of covalent bonds.

The (a)   is the minimum voltage required to observe significant current flow in a forward-biased p-n junction diode.

In a forward-biased p-n junction diode, the majority charge carriers move:

• • a) From p-side to n-side.

• • b) From n-side to p-side.

• • c) Both ways.

• • d) None of the above.