ET 212 Final Examination Answers – Grantham
Select True / False from the following :
The two basic kinds of transistor circuits are amplifying and switching.
True
False
The bridge rectifier is similar to a full-wave rectifier because it produces a full-wave output voltage.
True
False
A semiconductor is an element with electrical properties between those of a conductor and those of an insulator.
True
False
The dc beta is defined as the dc collector current divided by the dc emitter current.
True
False
An ideal diode acts like a switch that closes when forward-biased and opens when reverse-biased.
True
False
With a half-wave rectifier, the output frequency equals the input frequency.
True
False
Select Correct Answers from the Following
A pure semiconductor is also referred to as:
a clean room device | ||
intrinsic | ||
extrinsic | ||
Transistor |
4 points
Silicon that has been doped with a trivalent impurity is called a:
N-type semiconductor | ||
P-type semiconductor | ||
P-N junction | ||
covalent bond |
4 points
Question 9
In a silicon atom, what is the distance between the valence band and the conduction band called?
energy gap | ||
depletion layer | ||
P-N junction | ||
intrinsic |
4 points
Question 10
A diode is a nonlinear device because the graph of its current versus voltage is:
a straight line | ||
not a straight line | ||
inversely proportional to the resistance | ||
exponential |
4 points
Question 11
Ideally, a diode acts like a perfect conductor when forward-biased and:
like a perfect conductor when reverse-biased | ||
like a perfect semiconductor when reverse-biased | ||
like a perfect insulator when reverse-biased | ||
like a perfect diode when reverse-biased |
4 points
Question 12
A diode that exhibits high resistance in both directions when measured with an ohmmeter is:
shorted | ||
leaky | ||
open | ||
a properly operating diode |
4 points
Question 13
The knee voltage of a germanium diode is approximately ________.
0.7 V | ||
0.3 V | ||
1.7 V | ||
1.3 V |
4 points
Question 14
Much of the information on a manufacturer’s data sheet is:
necessary to understand diode circuits | ||
necessary to troubleshoot diode circuits | ||
obscure and of use only to circuit designers | ||
necessary only to electronics technicians |
4 points
Question 15
The output frequency of a half-wave rectifier is:
twice the input frequency | ||
half the input frequency | ||
equal to the input frequency | ||
four times the input frequency |
4 points
Question 16
A step-up transformer will produce a secondary voltage that is:
smaller than the primary | ||
equal to the primary | ||
larger than the primary | ||
rectified. |
4 points
Question 17
What is the name of the circuit shown in the Figure 1 below?
Figure 1
half-wave rectifier | ||
full-wave rectifier | ||
bridge rectifier | ||
voltage doubler |
4 points
Question 18
Which region of the transistor is physically the largest?
collector | ||
emitter | ||
base | ||
beta |
4 points
Question 19
Kirchhoff’s current law describes transistor currents as follows:
emitter current equals the sum of collector and base currents. | ||
collector current equals the sum of base and emitter currents. | ||
base current equals the sum of collector and emitter currents. | ||
emitter current equals collector current minus the base current. |
4 points
Question 20
Refer to Figure 2 below, what is the possible problem if VB is equal to 0 V and VC is equal to 15 V?
Figure 2
transistor is shorted | ||
RB is open | ||
VCC is 0 V | ||
transistor is blown open |
4 points
Question 21
Refer to Figure 2, what is the possible problem if VB is equal to 15 V and VC is equal to 15 V?
Figure 2
transistor is blown open | ||
VBB is 0 V | ||
transistor is shorted | ||
VCC is 0 V |
4 points
Question 22
Using the load line shown in Figure 3, what is the transistor’s collector current if biased at the point labelled Q?
Figure 3
1.5 mA | ||
3 mA | ||
4.5 mA | ||
7 mA |
4 points
Question 23
In the circuit shown in the Figure 4 below, calculate the saturation current?
Figure 4
4 points
Question 24
In the Common Collector (CC) circuit of Figure 5 below consider β = 49 and VBE = 0.7 V.
Figure 5
Find the following:
IB
IE
VCE
VE
VB
20 points