In a forward biased diode, current is carried by ?
- majority carriers
- minority carriers
- both
Diodes are ?
- conductors
- semi-conductors
- nsulators
A band pass filter excludes frequencies ?
- below the frequency required only
- above and below the frequency required
- above the frequency required only
A zener diode is designed to operate ?
- below its breakdown voltage
- either above or below its breakdown voltage
- above its breakdown voltage
A triac is a type of ?
- thermistor
- transistor
- thyristor
When a PN junction is forward biased, it conducts via ?
- intrinsic carrier
- majority carrier
- minority carrier
If the reverse bias voltage across a diode is too high ?
- load current reduces to zero
- load current increases rapidly
- load current reverses
An LED which emits green light uses ?
- gallium phosphide
- gallium arsenide
- gallium arsenide phosphide
N' type materials are doped with ?
- acceptors
- acceptors and donors
- donors
In an NPN transistor the P is the ?
- collector
- emitter
- base
The rotor of a magnesyn transmitter is ?
- a permanent magnet
- an ac electromagnet
- a dc electromagnet
What device transfers one energy type to another ?
- Transponder
- Transducer
- Transmitter
What control system is used on an input that gives a controlled predetermined output?
- Control Servo
- Closed Loop
- Open Loop
A rate control servo system with a steady input voltage will give ?
- decreasing speed
- increasing speed
- constant speed
The phase difference between the supplies of a two phase induction motor is ?
- 90°
- 180°
- 0°
An LVDT has ?
- an output winding which is wound in series opposition
- an input winding whose voltage will change with load movement
- an output winding whose voltage and frequency is linear to load angular movement
In a synchro system, if two stator lines are crossed the receiver will ?
- be 180° out
- not be affected
- reverse direction
A control synchro system pointer is ?
- actuated by a permanent magnet
- displaced by the torque of the stator
- motor driven
TR is the abbreviation for a ?
- transmitter Resolver
- torque Receiver
- torque Rynchro
What power is required for a desynn indicator system ?
- DC
- AC 400 Hz
- AC 50 Hz
