WorksheetsModule 04: Electronic Fundamentals
Total questions: 55
Worksheet time: 30mins
If light entering a photo transistor decreases, the current to the collector.
In a diode, which type of material is used?
N type material
P type material
Avalanche breakdown occurs when.
Reverse bias exceeds a certain value
Forward bias exceeds a certain value
Forward current becomes excessive
What gate does the following Boolean expression represent F = A+B+C.
NOR.
OR.
NOT.
A FET when compared to a junction transistor is.
low impedance.
current operated.
high impedance.
Current gain in a common emitter amplifier is given the symbol.
Β.
a.
Hcg.
Which mode of operation provides the best high frequency response? Common.
emitter.
base.
collector.
Which of the following describes the characteristics of a Thyristor?
A. High voltage handling.
B. High power handling.
C. High current handling.
Components on an integrated circuit are.
on the surface.
in the solid.
don't need them.
In an operational amplifier, the two input waves are the same amplitude, same frequency, but exactly anti-phase. What would the output be?
Double.
Zero.
Half.
In a semiconductor junction diode, electrons are the minority carriers.
A. within the P region.
B. within the N region.
C. in both the N and P regions.
PIN diodes are used mainly for.
Linear rectifiers
Fast switching devices
Voltage operated rectifiers
A silicon diode, when compared to a germanium diode has.
A. a higher forward bias voltage.
B. the same forward bias voltage.
C. less forward bias voltage.
A junction diode.
A. is similar to a vacuum diode but cannot rectify.
B. has one p-n junction.
C. can handle only very small currents.
A zener diode.
A. allows current to flow in one direction.
B. stabilizes voltage at a predetermined level.
C. acts like a switch.
To decrease the voltage gain of a common emitter amplifier you would increase the resistance in the.
base circuit.
emitter circuit.
collector circuit.
What gate does the following Boolean expression represent F = A.B.C.
AND.
OR.
NOT.
In an integrated circuit, the components are mounted.
by metal screws.
by metal oxide film.
by means of wires connecting them.
A resolver has.
3 coils on the rotor and 2 coils on the stator
2 coils on the rotor and 3 coils on the stator
2 coils on the rotor and 2 coils on the stator
A single integrated circuit Op Amp has how many pins?
7
8
4
When a hole diffuses from a p-region to the n-region it.
Becomes a minority carrier in the n-region
Lowers the potential barrier
Raises the potential barrier
A silicon bi-polar transistor with two depletion zones.
operates by varying electric fields.
is a voltage operated device.
consists of 3 slices of semiconductor material.
AC power to a synchro system is supplied to.
torque transmitter only
both the torque receiver and torque transmitter
torque receiver only
Why is a diode put in parallel with an LED?
A. To protect it from AC.
B. So it will work only above a certain voltage.
C. So it will work only below a certain voltage.
A germanium diode is used for.
A. rectification.
B. voltage stabilization.
C. modulation.
For conduction of a transistor, the emitter junction is.
forward or reverse as appropriate to the input signal.
reverse biased.
forward biased.
On an integrated circuit the hole in the top left corner is pin 1. The pins are counted.
clockwise.
from left to right.
anticlockwise.
A logic circuit with more than one gate will have.
2 or more outputs.
one of 2 states of logic output.
an analogue output.
What gives the colour of an LED?
A. The active element.
B. The plastic it is encased in.
C. The type of gas used inside it.
What is a schottky diode used for?
Rectification
Stabilization
Very high frequency applications
The junction barrier offers opposition to only.
Holes in the p-region
Free electrons in the n-region
Majority carriers in both regions
Light Emitting Diodes (LEDs).
A. emit light of only one wavelength dependent on type.
B. have very wide viewing angles.
C. are easily damaged if forward biased b more than 5V.
The voltage supply to a Complimentary Metal Oxide Semiconductor (CMOS) integrated circuit must be.
0 V is 5 V DC.
3V to 18V DC.
3V to 15V AC.
What type of diode would be used to stop voltage spikes across a coil of a relay?
Gunn diode
Double acting diode
Schottky diode
One characteristic of the emitter follower is.
low resistance output.
low current amplification.
high voltage amplification.
In the following Boolean algebra statement, which gate is described?. F = A + B + C.
And.
Or.
Not.
A differential synchro.
can be used as either a transmitter or a receiver
can only be used as a receiver
can only be used as a transmitter
The output of a tachogenerator is.
proportional to speed of rotation
proportional to position
proportional to acceleration
A non-inverting op-amp.
has an inverting input and a non-inverting output.
a non-inverting input connection only.
has a non-inverting input and an inverting output.
How are the pins numbered on an op-amp IC?
from left to right from the dot.
counter clockwise from the dot.
clockwise from the dot.
If forward bias is increased from zero on a p-n junction, a rapid increase in current flow for a relatively small increase in voltage occurs.
When the flow of minority carriers is sufficient to cause an avalanche breakdown
When the depletion layer becomes larger than the space charge area
Only after the forward bias exceeds the potential barrier
In a diode clamper, if the resistor is removed making the time constant equal to C x r where r is the reverse resistance of the diode, this will ensure
Long time constant
Short time constant
Very Long Time Constant
To enable an IMPATT diode to operate correctly, it must be.
Connected to a resonant circuit
Used in its reverse bias mode
Operated in its negative resistance range
For correct operation of a transistor, the following conditions must apply.
The base-emitter junction must be forward biased and the base-collector junction must be greater than 0.7 volts.
For an NPN transistor the base-emitter junction must be forward biased and for a PNP transistor the base emitter junction must be reverse biased.
The base-collector junction must be reverse biased and the base-emitter junction must be forward biased.
The 'null' point on a control synchro is when the two rotors are.
wired in series
at 90° to each other
parallel to each other
When testing the forward bias of a diode with a multimeter.
A. the positive lead of the ohmmeter is placed on the anode.
B. it does not matter which terminal the positive lead of the ohmmeter is placed.
C. the positive lead of the ohmmeter is placed on the cathode.
The current I/P and O/P waveforms in a common emitter amplifier are.
out of phase.
in phase.
90° out of phase.
Which way does conventional current flow in a PNP junction?
Emitter to base.
Collector to base.
Collector to emitter.
What are the ideal characteristics of an Op Amp?
Infinite gain, infinite input Impedance and infinite output impedance.
Infinite gain, infinite input Impedance and zero output impedance.
Low gain, infinite input Impedance and zero output impedance.
The phase difference between the supplies of a two phase induction motor is.
90°
180°
0°
When a positive voltage is applied to the base of a normally biased n-p-n common emitter amplifier.
the collector voltage goes less positive.
the emitter current decreases.
the base current decreases.
The position feedback from a potentiometer is.
anti-phase
in phase
90 degrees out of phase
A reduction from the optimum setting of the velocity feedback in a servo loop could cause.
instability
slow response
ow servo gain
The rotor of a desynn indicator is.
an electromagnet
a permanent magnet
an AC magnet
When a servomotor overshoots after a step input and oscillates it is.
under damped
over damped
critically damped
