EASA module 4 Electronic Fundamentals mcq 3

In the following Boolean algebra statement, which gate is described?
F = A + B + C
Ans a) Or
b) Not
c) And
*
In an E and I signal generator at datum, the voltage on the secondary windings
Ans a) are equal and opposite
b) is maximum
c) is zero
*
In a synchro resolver, the stator coils are at what angle in relation to one another?
a) 45 degrees
b) 80 degrees
Ans c) 90 degrees
*
In a synchrotel, the
a) rotor is fixed and the stator moves
b) rotor and stator is fixed
Ans c) stator is fixed and the rotor moves
*
On a PCB, a decoupling capacitor is used to get rid of transient currents between which points?
a) The electronic circuit and the aircraft ground
Ans b) Interspaced along the circuit
c) The negative rail and the rest of the circuit
*
What does the circuit shown below do?
a) Full wave rectifier
b) Voltage doubler
Ans c) Half wave rectifier
*
In an LED, what is used to make the colour?
Ans a) the doping material
b) The electrons
c) The plastic lens cover
*
An atom with 5 electrons in its outer shell is part of
Ans a) an N type material
b) a P type material
c) a C type material
*
In a FET, the junction connections are called
Ans a) drain, source and gate
b) base, collector and emitter
c) drain, collector and junctions
*
Avalanche breakdown occurs when
a) forward current becomes excessive
b) forward bias exceeds a certain value
Ans c) reverse bias exceeds a certain value
*
An AC servo demand can be converted to drive a DC motor by the introduction of a
a) rectifier
b) modulator
Ans c) demodulator
*
Synchro indicator systems are used when the indication is required to move
a) a fraction of the input distance
b) slower than the input rate
Ans c) at the same rate as the input
*
A linear variable differential transformer is used to measure position feedback where
a) 360o of rotation and high angular accuracy is required
b) accuracy is of limited importance but robust construction and reliability is important
Ans c) an output whose phase is related to direction of movement and amplitude linear over a wide range
*
A low frequency sinusoidal input will cause a closed loop servomechanism load to
Ans a) move to a demand position with no overshoot
b) move backwards and forwards at the input frequency
c) move to the demand position and then return to the datum position without any overshoot
*
To reduce oscillations about a demand position
a) the amount of velocity feedback would be decreased
Ans b) the amount of velocity feedback would be increased
c) the amount of position feedback would be increased
*
If a servo amplifier is suffering from drift
Ans a) the load would move to a new position, proportional to the drift and stay there
b) the load would move to a new position, proportional to the drift and then return back to the datum position
c) the load would oscillate about the datum position
*
In a transient velocity feedback circuit, the tachogenerator output is summated with the demand voltage
a) only when the load is slowing down
b) at all times when the load is moving
Ans c) only when the load is speeding up or slowing down
*
Positive feedback applied to a servomechanism
a) decreases the response of the system
b) opposes the demand signal
Ans c) increases the response of the system
*
A differential synchro rotor consists of
a) one winding parallel to the transmitter rotor
b) two windings at 90o apart
Ans c) three windings at 120o apart
*
A differential synchro transmitter used for addition has
a) the TDX S1 and S3 connections cross connected to the TX
b) the TDX S1 and S3 connections cross connected to the TR
Ans c) the TDX R1, R3 and S1, S3 connections cross connected to the TX
*
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
Ans a) only after the forward bias exceeds the potential barrier
b) when the flow of minority carriers is sufficient to cause an avalanche breakdown
c) when the depletion layer becomes larger than the space charge are