EEE 108 Midterm 2 UPDATED ACTUAL
Exam Questions and CORRECT Answers
Which of the following is true for a semiconductor doped P-type at 300°K ? - CORRECT
ANSWER The number of holes is greater than the number of free electrons
Which of the following is true for a semiconductor doped N-type at 300°K ? - CORRECT
ANSWER The number of holes is less than the number of free electrons
Which of the following is true ? - CORRECT ANSWER In doped Silicon at 300°K nearly
all the donor atoms have "donated" a free electron
In doped Silicon at 300°K nearly all the acceptor atoms are negatively charged immobile ions
Which of the following is true for the diffusion capacitance of a PN junction?
Select one:
a. All of these
b. The capacitance increases as temperature increases
c. The capacitance increases as the mean transit time increases
d. The amount of charge stored decreases as the forward bias increases
e. The capacitance decreases as the forward bias increases - CORRECT ANSWER The
capacitance increases as the mean transit time increases
As the forward bias voltage across a PN junction is increased, the potential barrier will
Select one:
a. Decrease
b. None of these
c. Stays the same
, d. No way to determine
e. Increase - CORRECT ANSWER Decrease
Which of the following is true for a zener diode used as a voltage reference?
Select one:
a. All of these
b. Once a zener diode is operating in the reverse breakdown region, the voltage across it doesn't
vary
c. The amount the reference voltage varies when the load current varies is called the load
regulation
d. The amount the reference voltage varies when the input supply voltage varies is called the
load regulation
e. The input supply voltage used must never be larger than the reverse breakdown voltage of the
zener diode - CORRECT ANSWER The amount the reference voltage varies when the
load current varies is called the load regulation
When does a diode "turn on" and start carrying a significant amount of current?
Select one:
a. When the voltage on the P side is higher than the voltage on the N side
b. None of these
c. When the voltage on the N side is higher than the voltage on the P side, but lower than the
breakdown voltage
d. When the voltage on the N side is higher than the voltage on the P side, and higher than the
breakdown voltage
e. When the voltage on the P side is higher than the voltage on the N side by at least 500mV
Correct - CORRECT ANSWER When the voltage on the P side is higher than the voltage
on the N side by at least 500mV
Exam Questions and CORRECT Answers
Which of the following is true for a semiconductor doped P-type at 300°K ? - CORRECT
ANSWER The number of holes is greater than the number of free electrons
Which of the following is true for a semiconductor doped N-type at 300°K ? - CORRECT
ANSWER The number of holes is less than the number of free electrons
Which of the following is true ? - CORRECT ANSWER In doped Silicon at 300°K nearly
all the donor atoms have "donated" a free electron
In doped Silicon at 300°K nearly all the acceptor atoms are negatively charged immobile ions
Which of the following is true for the diffusion capacitance of a PN junction?
Select one:
a. All of these
b. The capacitance increases as temperature increases
c. The capacitance increases as the mean transit time increases
d. The amount of charge stored decreases as the forward bias increases
e. The capacitance decreases as the forward bias increases - CORRECT ANSWER The
capacitance increases as the mean transit time increases
As the forward bias voltage across a PN junction is increased, the potential barrier will
Select one:
a. Decrease
b. None of these
c. Stays the same
, d. No way to determine
e. Increase - CORRECT ANSWER Decrease
Which of the following is true for a zener diode used as a voltage reference?
Select one:
a. All of these
b. Once a zener diode is operating in the reverse breakdown region, the voltage across it doesn't
vary
c. The amount the reference voltage varies when the load current varies is called the load
regulation
d. The amount the reference voltage varies when the input supply voltage varies is called the
load regulation
e. The input supply voltage used must never be larger than the reverse breakdown voltage of the
zener diode - CORRECT ANSWER The amount the reference voltage varies when the
load current varies is called the load regulation
When does a diode "turn on" and start carrying a significant amount of current?
Select one:
a. When the voltage on the P side is higher than the voltage on the N side
b. None of these
c. When the voltage on the N side is higher than the voltage on the P side, but lower than the
breakdown voltage
d. When the voltage on the N side is higher than the voltage on the P side, and higher than the
breakdown voltage
e. When the voltage on the P side is higher than the voltage on the N side by at least 500mV
Correct - CORRECT ANSWER When the voltage on the P side is higher than the voltage
on the N side by at least 500mV
