SEMICONDUCTORS

A silicon diode is forward-biased. You measure the voltage to ground from the anode at ________, and the voltage from the cathode to ground at ________. A.0 V, 0.3 V B.2.3 V, 1.6 V C.1.6 V, 2.3 V D.0.3 V, 0 V

B

As the forward current through a silicon diode increases, the internal resistance A.increases. B.decreases. C.remains the same.

B

Effectively, how many valence electrons are there in each atom within a silicon crystal? A.2 B.4 C.8 D.16

C

A diode conducts when it is forward-biased, and the anode is connected to the ________ through a limiting resistor. A.positive supply B.negative supply C.cathode D.anode

A

A reverse-biased diode has the ________ connected to the positive side of the source, and the ________ connected to the negative side of the source. A.cathode, anode B.cathode, base C.base, anode D.anode, cathod

A

An ideal diode presents a(n) ________ when reversed-biased and a(n) ________ when forward-biased. A.open, short B.short, open C.open, open D.short, short

A

For a forward-biased diode, the barrier potential ________ as temperature increases. A.decreases B.remains constant C.increases

A

Reverse breakdown is a condition in which a diode A.is subjected to a large reverse voltage. B.is reverse-biased and there is a small leakage current. C.has no current flowing at all. D.is heated up by large amounts of current in the forward direction.

A

The most common type of diode failure is a(n) ________. A.open B.short C.resistive

A

For a forward-biased diode, as temperature is ________, the forward current ________ for a given value of forward voltage. A.decreased, increases B.increased, increases C.increased, decreases D.decreased, decreases

B

Single-element semiconductors are characterized by atoms with ____ valence electrons. A.3 B.4 C.5 D.2 E.none of the above

B

The maximum number of electrons in each shell of an atom is A.2. B.2n2 where n is the number of the shell. C.4. D.8.

B

The movement of free electrons in a conductor is called A.voltage. B.current. C.recombination. D.equilibrium.

B

Under normal conditions a diode conducts current when it is A.reverse-biased. B.forward-biased. C.avalanched. D.saturated.

B

What occurs when a conduction-band electron loses energy and falls back into a hole in the valence band? A.doping B.recombination C.generation

B

You have an unknown type of diode in a circuit. You measure the voltage across it and find it to be 0.3 V. The diode might be A.a silicon diode. B.a germanium diode. C.a forward-biased silicon diode. D.a reverse-biased germanium diode.

B

A silicon diode measures a low value of resistance with the meter leads in both positions. The trouble, if any, is A.the diode is open. B.the diode is shorted to ground. C.the diode is internally shorted. D.the diode is working correctly.

C

An n-type semiconductor material A.is intrinsic. B.has trivalent impurity atoms added. C.has pentavalent impurity atoms added. D.requires no doping.

C

As the forward current through a silicon diode increases, the voltage across the diode A.increases to a 0.7 V maximum. B.decreases. C.is relatively constant. D.decreases and then increases.

C

Doping of a semiconductor material means A.that a glue-type substance is added to hold the material together. B.that impurities are added to increase the resistance of the material. C.that impurities are added to decrease the resistance of the material. D.that all impurities are removed to get pure silicon.

C

The boundary between p-type material and n-type material is called A.a diode. B.a reverse-biased diode. C.a pn junction. D.a forward-biased diode.

C

The term bias in electronics usually means A.the value of ac voltage in the signal. B.the condition of current through a pn junction. C.the value of dc voltages for the device to operate properly. D.the status of the diode.

C

What types of impurity atoms are added to increase the number of conduction-band electrons in intrinsic silicon? A.bivalent B.octavalent C.pentavalent D.trivalent E.none of the above

C

Which statement best describes an insulator? A.A material with many free electrons. B.A material doped to have some free electrons. C.A material with few free electrons. D.No description fits.

C

An atom is made up of A.protons. B.neutrons. C.electrons. D.all of the above

D

The forward voltage across a conducting silicon diode is about A.0.3 V. B.1.7 V. C.-0.7 V. D.0.7 V.

D

The wide end arrow on a schematic indicates the ________ of a diode. A.ground B.direction of electron flow C.cathode D.anode

D

There is a small amount of current across the barrier of a reverse-biased diode. This current is called A.forward-bias current. B.reverse breakdown current. C.conventional current. D.reverse leakage current.

D

What factor(s) do(es) the barrier potential of a pn junction depend on? A.type of semiconductive material B.the amount of doping C.the temperature D.all of the aboveE.type of semiconductive material and the amount of doping but not the temperature

D