Worksheetsdiodes
Total questions: 20
Worksheet time: 10mins
Which of the following impurities could be used to convert intrinsic silicon to extrinsic P type silicon?
Aluminium.
Germanium
Arsenic
Zinc.
Which of the following values represents a typical junction potential of a silicon diode?
0.2V
0.6V
1.6V
3.3V
Which of the following is a common application for Zener diodes.
Demodulation.
AC rectification.
Voltage regulation.
Input protection.
Which type of transformer is required to create a 180 degree input to a rectifier?
center-tapped secondary
step-down secondary
stepped-up secondary
split winding primary
The dc current through each diode in a bridge rectifier equals:
the load current
half the dc load current
twice the dc load current
one-fourth the dc load current
Since diodes are destroyed by excessive current, circuits must have:
higher voltage sources
current limiting resistors
more dopants
higher current sources
A filtered full-wave rectifier voltage has a smaller ripple than does a half-wave rectifier voltage for the same load resistance and capacitor values because:
there is a shorter time between peaks
there is a longer time between peaks
the larger the ripple, the better the filtering action
none of the above
Testing a good diode with an ohmmeter should indicate
high resistance when forward or reverse biased
low resistance when forward or reverse biased
high resistance when reverse biased and low resistance when forward biased
high resistance when forward biased and low resistance when reverse biased
The peak inverse voltage (PIV) across a nonconducting diode in a bridge rectifier equals approximately:
half the peak secondary voltage
twice the peak secondary voltage
the peak value of the secondary voltage
four times the peak value of the secondary voltage
A pn junction allows current flow when
the p-type material is more positive than the n-type material
the n-type material is more positive than the p-type material
both the n-type and p-type materials have the same potential
there is no potential on the n-type or p-type materials
When a diode is forward biased, the voltage across it
is directly proportional to the current
is inversely proportional to the current
is directly proportional to the source voltage
remains approximately the same
Why is heat produced in a diode?
due to current passing through the diode
due to voltage across the diode
due to the power rating of the diode
due to the PN junction of the diode
When checking a diode, low resistance readings both ways indicate the diode is:
open
satisfactory
faulty
not the problem
In a diode schematic, the anode is represented by a(n):
triangle
vertical line
zig-zag line
element indicator
An IC regulator receives an overload; it will:
shut down
compensate for heat
provide more voltage
sample and adjust
Rectifier output polarity depends upon:
cycles of input
capacitor polarity
half or full wave
diode installation
With a 12 V supply, a silicon diode, and a 370-ohm resistor in series, what voltage will be dropped across the diode?
0.3 V
0.7V
0.9 V
1.4 V
If the frequency of the applied ac signal to a half-wave rectifier is 60 Hz, the frequency of the pulsating dc output will be
30 Hz
60 Hz
90 Hz
120 Hz
Thermal shutdown occurs in an IC regulator if:
power dissipation is too high
internal temperature is too high
current through the device is too high
load resistance increases
With a half-wave rectified voltage across the load resistor, load current flows for what part of a cycle?
0 degrees
90 degrees
180 degrees
360 degrees
