5. Digital techniques / Electronic instrument systems - Q&A

When removing a PC card from an ESDS assembly ensure a low current path between

• aircraft and ground.
• you and the assembly.
• you and the aircraft.

A dot matrix/LED construction is

• 4*7 or a 9*5 rolling end display.
• 5*9 or a 4*7 rolling end display.
• 4*7 or a 5*7 rolling end display.

What is the equivalent of this gate?

• = (NOT-A + NOT-B)
• = (NOT-A . NOT-B)
• = NOT-(A.B) + (A)

In a flight director, how are small deviations corrected?

• Pilot input.
• Servo motor.
• Gyro torque.

Data is usually stored in

• RAM.
• ROM.
• ALU.

A DAC uses a precision amplifier to

• ensure the output voltages remain accurate.
• compensate for input resistor temperature.
• ensure the input voltage remains accurate.

An aircraft may have been HIRF affected.

• A bonding load check is required.
• A static wick check is required.
• A full wiring loom check needed.

2D in decimal is

• 43.
• 45.
• 41.

On an EHSI in weather radar mode, a severe storm would be shown as

• green areas with grey surrounds.
• red areas with black surrounds.
• blue areas with grey surrounds.

A NAND gate has inputs A and B and output C. If the output was zero, what are the inputs?

• A=1 B=1.
• A=0 B=0.
• A=1 B=0.

What Logic Gate does this switch circuit indicate?

• SR gate
• DC gate
• OR gate

Bubble memory stores data on

• ferrite core substrate.
• semiconductor material.
• magnetic tape material.

An octal format hexadecimal number 3F written as binary would be

• 110 111.
• 111 111.
• 101 011.

An ALU performs the following

• Arithmetic and Logic operations only.
• Input/Output operations, Arithmetic, Logic Functions.
• Arithmetic, Logic, Branching and Find Instructions.

What would be the outputs of this circuit, if A=1 B=1 C=0?

• 0, 1
• 1, 1
• 1, 0

Electrostatic discharge occurs when

• materials of similar composition are physically separated from one another.
• materials of the same potential are placed into direct contact with each other.
• materials of different potential are brought in close proximity to each other.

A semiconductor which emits photons and releases electrons when stimulated by photons is called

• a power diode.
• a laser diode.
• a zener diode.

In order to maintain HIRF protection, bonding checks between airframe and electrical components carrying voltages greater than 50 volts RMS or DC or main earth return should not exceed

• 5 ohm.
• 1 ohm.
• 3 ohm.

How many address lines would be needed for an 8 line MU?

• 2.
• 3.
• 4.

What does 1 represent in an analogue system?

• Switches open, demagnetised
• Switches closed, magnetised
• Switches open, unmagnetised

0011011000101001 when transferred to computer language this information can be a representation of

• binary, octal or hex coded data.
• hex, octal and binary numbers.
• hex, octal and decimal numbers.

ACARS is an acronym for

• Airframe Communicating Addressing and Reporting System.
• Airborne Communicating Addressing and Reporting System.
• Aircraft Communicating Addressing and Reporting System.

In an Arinc 429 Word label-representing heading is 320, this is represented in bits 1- 8 as

• 01011001.
• 00001011.
• 01101000.

How is the word label 206 written in ARINC 429?

• Decimal 010110.
• Octal 01100001.
• Hex value 0x86.

Two connected fibre optic cable ends are parallel but not quite touching. This is called

• end to end coupling.
• butt joint coupling.
• lateral gap coupling.