Download Avionics Technician Certification Exam: 100 Questions with Verified Answers and more Exams Basic Electronics in PDF only on Docsity!
AVIONICS TECHNICIAN CERTIFICATION EXAM
COMPLETE 100 QUESTIONS AND CORRECT
DETAILED ANSWERS (VERIFIED ANSWERS)
1. Which component regulates aircraft DC bus voltage? A. Transformer B. Autotransformer C. Generator Control Unit (GCU) D. Voltage Regulator Regulators maintain stable output voltage regardless of generator load. 2. What is the primary purpose of an Inertial Reference Unit (IRU)? A. Fuel balancing B. Providing attitude, heading, and acceleration data C. Brake control D. Cabin pressure monitoring IRUs supply orientation and motion data independent of external signals. 3. Which frequency band is used by VOR navigation? A. HF B. VHF C. UHF D. LF VOR systems function in the VHF range around 108–118 MHz. 4. TCAS primarily prevents: A. Ground collisions B. Mid-range navigation drift
C. Midair collisions D. Weather impacts TCAS detects nearby aircraft using transponder signals.
5. What color identifies an avionics bonding strap? A. Blue B. Red C. Green or bare metal D. Yellow Bonding straps are usually unpainted or green for grounding continuity. 6. The term “avionics bus” refers to: A. Physical wiring harness only B. Battery output C. A power distribution line for avionics D. A ground-return path Buses distribute electrical power to selected avionics equipment. 7. Which instrument uses a pitot tube? A. Altimeter B. Vertical speed indicator C. Heading indicator D. Airspeed indicator Pitot pressure directly drives the airspeed indicator. 8. Autopilot servo actuators convert electrical commands into: A. Heat B. Mechanical motion C. Magnetic flux
13. Which bus powers essential avionics during generator failures? A. Cabin bus B. Essential/Emergency bus C. Landing gear bus D. Cargo bus Essential bus supports critical flight instrumentation. 14. The ELT transmits emergency signals on: A. 108 MHz B. 800 MHz C. 406 MHz D. 10 MHz 406 MHz is the international digital distress frequency. 15. What device isolates electrical faults to prevent full bus failure? A. Switch B. Battery C. Circuit breaker D. Ammeter Circuit breakers protect system wiring and components. 16. An FMS integrates: A. Only flight controls B. Only fuel valves C. Navigation, performance, and guidance data D. Galley functions FMS centralizes aircraft navigation and flight planning.
17. The symbol Ω refers to: A. Voltage B. Current C. Resistance D. Impedance only Omega denotes resistance in ohms. 18. What protects against electromagnetic interference? A. Nylon loom B. Plastic tape C. Shielded wire D. Cotton braid Shielding reduces radiated and received interference. 19. A CVR records: A. Autopilot positions B. Cockpit audio and communication C. Fuel pressure D. Weather radar output Cockpit Voice Recorders store audio from crew communication. 20. The unit converting AC to DC is the: A. Inverter B. Rectifier C. Transformer D. Alternator Rectifiers convert AC to DC. 21. Which radar mode detects precipitation?
C. CDI or PFD D. Weather radar CDIs and PFDs show localizer and glideslope data.
26. A transceiver combines: A. Receiver + amplifier B. Receiver + transmitter C. Transmitter + motor D. Motor + processor “Transceiver” = transmit + receive. 27. A short circuit is best defined as: A. Open circuit B. Unintended low-resistance path C. Correct resistance reading D. High impedance fault Short circuits cause excessive current flow. 28. Autothrottle systems adjust: A. Flaps B. Rudder C. Landing gear D. Engine thrust Autothrottles control power settings automatically. 29. The emergency bus is normally powered by: A. Pitot heat B. Battery or standby generator C. Cabin lights
D. Gear retraction pump Emergency bus runs from backup power sources.
30. Which is a digital data bus? A. Coax LMR B. 115 VAC feeder C. ARINC 429 D. Bonding strap ARINC 429 is the standard avionics data bus. 31. A magnetometer measures: A. Temperature B. Earth's magnetic field C. Altitude D. Vibration Magnetometers support heading systems. 32. Which tool verifies antenna VSWR? A. Ammeter B. SWR meter C. Voltmeter D. Clamp meter VSWR checks antenna tuning & efficiency. 33. TCAS operates using: A. Radar reflectivity B. LF transmissions C. Transponder interrogation D. GPS only TCAS relies on transponder replies for traffic detection.
38. A gimbal is used in: A. ELT B. Transponder C. Gyroscopic instruments D. Oil pumps Gimbals allow gyros to remain stable regardless of aircraft motion. 39. Inverters convert: A. DC → DC B. AC → DC C. DC → AC D. AC → AC Inverters create AC from DC sources. 40. Which antenna is typically used for VHF COM? A. Loop B. Dish C. Blade/whip D. Patch Blade or whip antennas suit VHF communication ranges. 41. The FDR records: A. Cabin temperature B. Pilot heart rate C. Flight parameters (speed, altitude, control input) D. Catering data Flight Data Recorders store performance variables. 42. What is the purpose of a resolver?
A. Encoding audio B. Storing memory C. Converting mechanical position to electrical signals D. Cooling avionics Resolvers translate angle to electrical outputs.
43. “Line replaceable unit” means: A. Component never replaced B. Removed quickly on the aircraft line C. Requires full shop teardown D. Installed only once LRUs are designed for rapid replacement. 44. Cabin pressure controllers rely on: A. Airspeed B. Fuel flow C. Differential pressure sensors D. Engine RPM Controllers monitor cabin-to-external pressure differences. 45. An RF connector used frequently in avionics is: A. RJ- 45 B. USB-C C. BNC D. HDMI BNC connectors are standard for RF lines. 46. Which displays heading information? A. VSI B. HSI
D. Servo vibration Excess heat quickly degrades avionics reliability.
51. What is the purpose of an ADF system? A. Display glideslope B. Detect TCAS traffic C. Provide bearing to an NDB D. Display radar altitude ADF needles point toward the non-directional beacon. 52. Which device provides radio altitude? A. GPS receiver B. Radar altimeter C. ADC D. VOR receiver Radar altimeters measure actual height above terrain using RF signals. 53. Which system assists in stability during autopilot yaw control? A. EFIS B. VOR C. Yaw damper D. ELT Yaw dampers reduce Dutch roll tendencies. 54. What does “squawk” refer to? A. A radio failure B. A transponder code C. A lightning strike
D. A servo jam ATC assigns squawk codes for aircraft identification.
55. What is used to prevent moisture in avionics compartments? A. Oil B. Desiccant packs C. Alcohol D. Plastic wrap Desiccants absorb humidity to prevent corrosion. 56. The symbol μF indicates: A. Ohms B. Microfarads (capacitance) C. Frequency D. Current μF is the standard unit for capacitance. 57. The autopilot’s pitch channel controls: A. Rudder B. Ailerons only C. Elevator movement D. Landing gear Pitch control adjusts elevator position. 58. DME provides: A. Bearing B. Altitude C. Slant-range distance D. Wind direction DME calculates distance using transmitted pulse timing.
63. A coaxial cable’s shield should be grounded at: A. Both ends always B. One or both ends depending on design C. Only in mid-span D. Never Grounding depends on EMI strategy and system requirements. 64. Fiber-optic lines are used because they are: A. High-voltage tolerant B. Cheaper C. Immune to EMI and lightweight D. Detected by radar Optics eliminate electrical interference problems. 65. An altimeter setting corrects for: A. Speed B. Temperature C. Atmospheric pressure variations D. Humidity Changing barometric pressure changes displayed altitude. 66. What does an autopilot trim servo do? A. Controls cabin temp B. Maintains aircraft in trimmed condition C. Engages flap position D. Sets transponder code Trim servos adjust trim tabs automatically. 67. Which radio band is used for HF communications?
A. 118–136 MHz B. 960–1215 MHz C. 2–30 MHz D. 406 MHz HF occupies long-range bands in the low MHz range.
68. The FMS typically outputs guidance to the: A. Fire system B. Hydraulic pumps C. Autopilot and flight director D. Beacon lights FMS provides lateral/vertical navigation cues. 69. A “black box” is composed of the CVR and: A. VOR B. FDR C. ELT D. ADC Black boxes record audio + flight parameters. 70. Which sensor measures AoA? A. Radar antenna B. Magnetometer C. Vane or pressure-difference AoA probe D. TCAS antenna AoA vanes detect angle of airflow. 71. What does a glide slope transmitter operate on? A. GPS L B. HF band
D. Marker beacon GPS provides global navigation.
76. The symbol “kHz” stands for: A. Kilovolts B. Kilohertz C. Kilograms D. Kilo-ohms kHz measures frequency. 77. A typical audio panel allows: A. Fuel switching B. Trim adjustments C. Radio selection and intercom control D. Flap selection Audio panels route communications and NAV audio. 78. What does a tach generator measure? A. Voltage B. RPM C. Density D. Fuel flow Tach generators create voltage proportional to rotational speed. 79. The standby attitude indicator is usually powered by: A. VOR B. ADF C. Battery or independent power D. Autothrottle Standby instruments use independent power for reliability.
80. What does an antenna coupler do? A. Cools the antenna B. Measures VSWR C. Matches transmitter to antenna for HF tuning D. Stores frequencies Couplers tune HF antennas across wide bands. 81. The green arc on an airspeed indicator represents: A. Overspeed B. Normal operating range C. Stall range D. VNE Green arc indicates safe flight speeds. 82. A servo clutch is used to: A. Store data B. Track GPS C. Allow pilot override of autopilot servos D. Power displays Clutch permits manual control without damage. 83. TAWS Mode 2 warns of: A. Battery overheat B. Excessive terrain closure rate C. Fuel imbalance D. Cabin smoke Mode 2 alerts when terrain is being approached too rapidly.
