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WorksheetsFundamental Electronics
Total questions: 100
Worksheet time: 6hrs 28mins
The process of adding an impurity to an intrinsic semiconductor is called
Doping
Ionization
Recombination
Atomic modification
What is the most common semiconductor material used for producing integrated circuits
Quartz
Silicon
Diamond
Tantalum
Which of the following is a symbol of NPN transistor ?
This is a graph that is seen on CRO. How is it change after full wave rectification process?
Who contribute to the current in a semiconductor
electrons only
holes only
negative ions
both electrons and holes
The gate of a TRIAC is used to
To trigger the conduction
To forward biase
To reverse biase
A diode allows current flow
in one direction only
if it is out of phase with the voltage
if it lags the voltage by 90 degrees
When positive terminal is connected to anode and negative terminal connected to cathode,then the diode is
Forward biased
Reverse biased
in blocking mode
When a multimeter is set to the diode test position,and show around 0.7 volts on the multimeter when tested in the forward bias direction and show the internal voltage of the meter when tested in reverse bias,then the diode is
Serviceable condition
Unserviceable condition
Open ciruited
Diodes are connected in parallel when
when the forward current exceeds the maximum forward current of an individual diode
when the forward voltage exceeds the maximum forward current of an individual diode
If the voltages to be blocked by the diodes is equal to the maximum permissible reverse voltage of a diode
Which switch can control the both lights L1 & L2
S1
S2
S1 & S2
A free wheeling diode connected across a relay coil is used to
short-circuit the back-emf that occurs when
switching off relays
cause a delay in switching on
allow the coil to energize with only one polarity
The circuit shown below is a
Full wave bridge rectifier
Voltage doubler
Half-wave rectifier
Ziner Diode is used as
Voltage regulator
Voltage divider
Rectifier
This symbol represents
a photodiode
a laser diode
a LED
When light shines on LDR the resistance will
Decrease
Increase
No effect with light
The following figure represents:
NPN
PNP
MOSFET
The figure shown is
TRIAC
DIAC
LED
An ideal Operational Amplifier (Op Amp) should have
infinite input impedance and zero output impedance
zero input impedance and zero output impedance
infinite input impedance and infinite output impedance
The process in which the copper laminated boards are used,then conducting paths and eyelets are to be located are protected by applying paint in a silk screen printing process or by light sensitive paint.Then the unprotected areas are etched away is know as
Subtractive Process
Additive process
Integrated process
A "closed loop" control system
makes the system far more accurate as any variations in power supply or in amplifier gain can be overcome
does not detect errors at the output
uses no feedback to assist the input
The maximum voltage for a stator coil is generated in which stator coil
S2
S1
S3
A resolver synchro would have
Coils in the stator and the rotor which are displaced by 90 degrees from each other
Coils in the stator and the rotor which are displaced by 120 degrees from each other
Coils in the stator and the rotor which are displaced by 40 degrees from each other
The method used for position sensing in systems such as doors and landing gear.
Proximity switches
Pressure Switches
Temperature Switches
In a typical Control Synchro Servo Mechanism, velocity feedback is provided for dampening by
a tacho/rate generator connected between the Servo Motor and the Servo Amplifier
a capacitor between the Control Transformer (CT) and the Servo Amplifier
rotating the rotor of the Control Transformer (CT) to align it with the Stator field
The figure shown is
Integrator
Inverter
Adder
Figure shown is
Operational Amplifier
Integrated Circuit
AND Gate
Figure shown is
Diode
LED
Photo Diode
Figure Shown is
Half Wave Rectifier
Full Wave Rectifier
Amplifier
The wiring Symbol Shown here is
NPN Transistor
PNP Transistor
Diode
Figure shown here is
LDR
LED
SCR
The Figure shown here is
Differentiator
Integrator
Adder
The figure shown here is
Varistor
LDR
Thyristor
What diode emits photons when forward biased?
LED
Photodiode
Transistor
The angle between the stator coils in a synchro resolver is
90
45
180
Optical coupling devices
contain at least one transmitter chip on the input side and a receiver chip on the output side
Contain two transformers
Contains a transformer and a rectifier
An "open loop" control system
will not detect errors at the output
uses negative feedback to “back off” the input
Control the output
Diodes are connected in series when
If the voltages to be blocked by the diodes exceeds the maximum permissible reverse voltage of a diode
If the voltages to be blocked by the diodes is less than the maximum permissible reverse voltage of a diode
If the current to be blocked by the diodes exceeds the maximum permissible forward current of a diode
Photodiodes are always connected in
reverse biase
Forward biase
doesnot affect the polarity
Arrangements of several electronic components including transistors, resisters and capacitors in a common housing is called
Integrated circuit
Diode
Transistor
The process in which the non laminated boards are used, then the conducting paths are galvanized onto the board is know as
Additive process
Subtractive Process
Integrated process
LVDT stands for
Linear Variable Differential Transformer
Low Voltage Differential Transistor
Low Voltage Differential Transformer
How a thyristor can return to its high resistance state
By bringing the electrical current below holding current ( IH )
By negative current applied to the control electrode
the gate current is removed
In which circuit does the bulb light up?
What are the names of the terminals X, Y and Z?
X = Base, Y = Collector, Z = Emitter
X = Emitter, Y = Base, Z = Collector
X = Collector, Y = Base, Z = Emitter
X = Collector, Y = Emitter, Z = Base
How many terminals are there in a transistor....?
1
2
3
4
A differential synchro rotor consists of
one winding parallel to the transmitter rotor
two windings at 90° apart
three windings at 120° apart
A synchro rotor indicator moves
faster than the input rate
slower than the input rate
at the same rate as the input
Torque synchro systems are normally used when the
mechanical load is low
mechanical load is high
system accuracy is of extreme importance
In a servo control system, mechanical displacement is converted into electrical signals by a
transmitter
transducer
transformer
The power supply to a torque synchro system is connected to
the transmitter stator
the transmitter rotor only
the transmitter and receiver rotors
When a thyristor is switched on its resistance
increases
decrease
does not change
The electrodes of an SCR/thyristor are called
anode, cathode, source
source, drain, gate
gate, cathode, anode
A germanium diode ______________ than a silicon diode
is less affected by changes in temperature.
has a smaller reverse current
has a lower breakdown voltage
When a PN junction is reverse biased the negative lead of the battery is connected to the
P type material
N type material
barrier layer
The forward bias voltage of a germanium diode is ___________ a silicon diode
lower than
higher than
the same as
The anode of a diode is connected to a +4v DC supply and the cathode is connected to a +2v DC supply. The diode is
forward biased not conducting
reverse biased not conducting
forward biased conducting
The forward volts drop across a conducting silicon diode is approximately
0.7 V
0.2 V
1.6 V
To check the reverse resistance of a diode with a multimeter, the positive lead is connected to the
anode
cathode
either anode or cathode
Reverse bias
lowers the potential barrier
raises the potential barrier
greatly increases the majority carrier current
The temperature coefficient of a thyristor is
positive
negative
zero
The forward and reverse resistance of a serviceable diode is
high in both directions
high in one direction and low in the other direction
low in both directions
For a NPN transistor to conduct the collector circuit has to be
at earth potential
more positive than the base
less positive than the emitter
The type of diode having maximum forward biased current lies far below one ampere?
Microdiode
Rectifier Diode
High power diode
Two same diodes with a maximum reverse voltage of 60 V are connected in series and the voltage applied in reverse direction is 100 V, then how much is the voltage drop in each diode?
Both diode have 50V
Both diode have 60V
Both diode have 100V
If the diode is faulty in the open circuit condition then the resistance reading is
will be high in both directions
will be low in both directions
will be high in one direction and low in other directions
Rectifier use mainly which component?
Diode
LDR
VDR
Image shown here is
Z-Diode
LED
Photodiode
LED 's are used in
Forward biased direction
Reverse biased direction
Work in both direction
LDR stands for
Light Dependant Resistor
Light Diode Resistor
None of the above
LDR used in
Forward biased direction
Reverse biased direction
Polarity not matters
Smoothing of rectifier output is done by
Filters
Transistors
resisters
What happens to a diode when it is wired in reverse bias direction?
It shows low resistance
It shows high resistance
It amplifies the signal
What is the main cause of residual reverse-biased current in semiconductor diodes?
Impurities in the crystal
High Temperature
Low voltage
What is the maximum permissible reverse voltage for silicon diodes?
200 V
5KV
1KV
How many diodes are required for a bridge circuit in a three-phase system?
Four
Six
Eight
What determines the color of light emitted by an LED?
The semiconductor material used
The voltage applied
The current flowing through it
When the LVDT core is centered, the output voltage is:
Maximum
Zero
Negative
Inductance transmitters are mainly used to measure:
Position or speed
Voltage
Temperature
When a ferrous target approaches an inductive proximity sensor:
Inductive reactance decreases
Inductive reactance increases
Resistance becomes zero
Proximity switches are commonly used in:
Landing gear and door position sensing
Fuel quantity measurement
Light dimmer circuits
Induced‑voltage sensors are frequently used for measuring:
Engine RPM
AC voltage
Fuel temperature
Capacitance transmitters are mainly used to measure:
Hydraulic pressure
Engine speed
Fuel quantity
A capacitance transmitter operates by changing:
Dielectric constant
Plate area
Supply frequency
Servo systems are used when:
Small torque is sufficient
Only DC power is available
Large rotation moments are required
To prevent oscillation, servo systems use:
Voltage regulators
Damping
Rectifiers
The process of returning a portion of the output to the input to maintain the desired output.
Feedback
Null
Damping
The difference between the output signal and the demanded signal is called
error signal
damping signal
deadband
In a synchro, maximum stator voltage is induced when:
Rotor axis aligns with stator coil
Rotor is at 90°
Rotor is unexcited
In an aligned synchro system, the current flow is:
Maximum
Zero except magnetizing current
Independent of alignment
Maximum torque occurs when the differential angle is approximately:
0°
45°
90°
If TX and TDX shafts rotate in the same direction, the result is:
Subtraction
Addition
Zero output
Resolvers are commonly used to:
Store electrical energy
Transmit torque
Split angles into sine and cosine components
Microdiodes are typically used in:
High‑power circuits
Communication equipment
Motor control systems
At absolute zero temperature, a semiconductor behaves as:
A conductor
A superconductor
An insulator
The charge transport in semiconductors using electrons and holes is called:
Bipolar conduction
Unipolar conduction
Metallic conduction
A photodiode is normally connected in:
Reverse bias
Forward bias
No bias
