Worksheets14.2.1 & 14.2.2 Quiz
Total questions: 42
Worksheet time: 21mins
What type of instrument is used to measure fuel level, temperature, and pressure?
Frequency counter
Oscilloscope
Moving coil instrument
Digital voltmeter
How does the output from a transducer in a moving coil instrument typically manifest?
As a resistance
As a frequency
As a current
As a voltage
What principle does a DC ratiometer operate on?
Producing opposing torques
Detecting temperature variations
Measuring voltage differences
Indicating frequency changes
In a moving coil instrument, what opposes the movement of the coil?
The magnetic field
The hairsprings
The power supply
The transducer
What happens to the pointer in a moving coil instrument when the deflecting force equals the controlling force?
It remains steady
It oscillates
It reverses direction
It moves to the maximum scale
What is the role of the variable resistor in a pressure indicator system?
To adjust the current flow
To measure temperature
To provide a constant voltage
To amplify the signal
How does the direction of current flow affect the magnetic field around a wire?
It determines the field's direction
It has no effect
It increases the wire's temperature
It changes the wire's resistance
What type of current does an AC ratiometer use?
Alternating current
High-frequency current
Direct current
Pulsating current
What is the effect of increasing current in a moving coil instrument?
The instrument shuts down
The hairsprings weaken
The pointer moves further over the scale
The pointer moves less
What is the purpose of the soft iron core in a moving coil instrument?
To reduce weight
To enhance the magnetic field
To provide insulation
To increase resistance
How do flux lines behave when they meet lines moving in the same direction?
They strengthen each other
They cancel each other
They become static
They reverse direction
What is the primary application of a moving coil instrument in aviation?
Navigating
Measuring altitude
Communicating
Monitoring engine parameters
What does the symbol ⊕ represent in current flow direction?
Current flowing away from the reader
Current flowing in a loop
Current flowing in a circuit
Current flowing towards the reader
What is the damping force in a moving coil instrument caused by?
Eddy currents
The power supply
The hairsprings
The magnetic field
In a moving coil instrument, what is the function of the pointer?
To display the pressure
To indicate the current level
To measure voltage
To show the fluid level
What type of magnet is used in a DC ratiometer?
Permanent U-shaped magnet
Neodymium magnet
Ferrite magnet
Electromagnet
What happens to the pointer when the torque in one coil exceeds the other in a DC ratiometer?
It remains stationary
It moves towards the stronger coil
It moves towards the weaker coil
It oscillates indefinitely
What is the primary measurement function of a moving coil instrument?
Pressure and fluid levels
Voltage
Frequency
Current
How does the construction of a moving coil instrument affect its performance?
It only affects the weight
It has no effect
It limits the types of currents measured
It determines the range of measurements
What is the role of the hairsprings in a moving coil instrument?
To balance the deflecting force
To provide electrical resistance
To amplify the current
To generate a magnetic field
In a moving coil instrument, what is the result of the coil being wound multiple times?
Reduced torque
Decreased accuracy
Enhanced sensitivity
Increased resistance
What happens to coil A as it moves into an area of weaker magnetic flux?
Its torque remains constant.
Its torque increases.
It stops moving.
Its torque gets weaker.
How does coil B respond when it is pulled into an area of stronger magnetic flux?
Its opposing torque gets stronger.
Its torque remains unchanged.
It becomes inactive.
Its torque decreases.
What occurs when the torques of the two coils are equal?
The instrument stops moving.
The instrument accelerates.
The instrument reverses direction.
The instrument continues to move.
What is the purpose of the weak spring fitted in the instrument?
To increase the speed of the instrument.
To enhance the torque of coil A.
To pull the pointer off scale during a power failure.
To stabilize the instrument's position.
In what applications can the DC ratiometer be used?
For indicating temperature and fluid level.
Only for measuring temperature.
Exclusively for fluid level indication.
Only for measuring pressure.
How does the impedance of a coil change when the soft iron core is moved into it?
Impedance remains the same.
Impedance fluctuates.
Impedance decreases.
Impedance increases.
What is the function of the shaded pole motors in the AC ratiometer?
To rotate the assembly in opposite directions.
To stabilize the power supply.
To create a magnetic field.
To measure temperature.
What happens to the torque of the more powerful motor in the AC ratiometer as it dominates?
It decreases as the assembly rotates.
It becomes irrelevant.
It remains constant.
It increases indefinitely.
What is the primary purpose of the hairspring in the direct driven indication system?
To stabilize the power supply.
To increase the speed of the pointer.
To enhance the torque of the magnet.
To provide a controlling force to the drag cup.
Why is the direct driven indication system impractical for most aircraft uses?
It is too expensive.
It is not accurate enough.
It is too complex to install.
It requires frequent servicing and has a limited life.
What does the tacho generator system consist of?
A complex electronic circuit.
A hydraulic pressure system.
A simple generator mounted on the engine and an instrument in the flight deck.
A series of mechanical gears.
What is the role of the drag cup in the direct driven indication system?
To create a magnetic field.
To follow the rotating magnetic field.
To stabilize the power supply.
To measure temperature.
How does the current supply affect the two coils in the AC ratiometer?
It is constant regardless of impedance.
It is divided based on their impedance.
It only affects coil A.
It is equal in both coils.
What happens to the pointer when the torques of the two motors in the AC ratiometer balance?
It reverses direction.
It continues to rotate.
It accelerates.
It comes to rest.
What type of transducer is commonly used for measuring fluid levels?
Magnetic transducer.
Capacitive transducer.
Optical transducer.
Thermal transducer.
Which method of engine speed measurement is most commonly used in small single-engine aircraft?
Tacho generator indicator.
Pulse probe indicator.
Direct driven indication.
What is the primary function of the pressure-operated capsule stack in the AC ratiometer?
To measure temperature.
To move the soft iron cores against a spring.
To increase the torque of the motors.
How does the frequency of the tacho generator output relate to engine speed?
It is inversely proportional to engine speed
It is directly proportional to engine speed
It remains constant regardless of engine speed
What is the function of the servo amplifier in a servo-operated tachometer indicating system?
To measure fuel flow
To amplify the error signal for the motor
To generate electrical power
What principle does the tacho probe system operate on?
Capacitive sensing
Thermal expansion
Electromagnetic induction
What is the purpose of the null monitor in the servo-operated tachometer system?
To detect failure in the servo circuit
To measure fuel efficiency
To provide backup power
