Electronic Devices and Circuit Theory, 9e (Boylestad)
Chapter 1: Semiconductor Diodes
1) An intrinsic semiconductor is one that is as pure as present-day technology can make it.
2) Electrons are the minority carriers in an n-type material.
3) Holes are the majority carriers in a p-type material.
4) The quantum-Volt (qV) is the unit of measurement for electron energy.
5) A free electron has a higher energy state than any that are bound to their nucleus.
6) Si and Ge both have negative temperature coefficients.
7) The amount of energy that is converted to heat at a silicon p-n junction can be a significant design consideration.
8) A normalized value has a reference magnitude of one.
9) The reverse breakdown voltage of an LED is typically less than 12 V.
10) The amount of photon energy emitted at the p-n junction of a silicon diode is negligible.
11) The characteristic of an ideal diode are those of a switch that can conduct current ________. A) in both directions
B) in one direction only
C) in both directions but in only one direction at a time
D) depends on the circuit it is used in
12) When a diode is doped with either a pentavalent or a trivalent impurity its resistance will ________. A) increase
C) make the resistance stable against variation due to temperature D) None of the above
13) To make a p-type of semiconductor material you need a doping material that is ________. A) pentavalent
14) The direction of the arrow in the diode symbol points in the direction of ________. A) positive terminal under forward bias
B) from n-type of semiconductor to p-type semiconductor material C) from p-type of semiconductor to n-type semiconductor material D) leakage current flow
15) The reverse saturation current of a diode will just about ________ for every 10°C rise in the diode temperature. A) double
C) increase proportionately with temperature
D) decrease proportionately with temperature
16) Increasing the temperature of a forward-biased diode ________. A) causes forward current to increase
B) causes forward current to decrease
C) has no significant effect on the forward current
D) None of these
17) The DC or the static resistance of the diode is given by ________. A) RD = [pic]
B) RD = [pic]
C) RD = [pic]
D) All of the above can be used.
18) The piecewise linear model, equivalent circuit of the diode consists of ________. A) a junction capacitor, a battery, a small resistor, and the ideal diode B) a battery, a small resistor, and the ideal diode
C) a battery and the ideal diode
D) the ideal diode
19) Some of the modern ohmmeters have a diode test setting. If you do not have one of these ohmmeters then to test the diode you need to check its resistance in the forward and the reverse direction. These resistances should be ________. A) relatively high in the forward direction and relatively low in the reverse direction B) relatively low in the forward direction and relatively low in the reverse direction C) relatively low in the forward direction and relatively high in the reverse direction D) relatively high in the forward direction and relatively high in the reverse direction
20) In the Zener region the current ________ and the voltage across the diode ________. A) is almost constant; can increase a lot
B) is almost constant; is almost constant
C) can increase a lot; is almost constant
D) can increase a lot; can increase a lot
21) Suppose that a particular Zener diode has a temperature coefficient of 0.00575. If the temperature of this Zener diode increases by 50° C, what is the change in Vz? A) 50 × 0.00575 = 0.2875
B) 5 × 0.00575 = 0.02875
C) 10 × 0.00575 = 0.0575
D) Cannot tell without looking at the circuit in which the Zener is used
22) An LED produces visible light when ________.
A) the electrons and the holes combine with each...