Practice Exam Questions And Correct

Rail Signal Technician Certification Practice Exam Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• What is the main function of a railway signal system?
• Increase train speed
• Ensure safe train movement
• Reduce fuel consumption
• Communicate passenger schedules

Rationale: Signals control train movements and prevent collisions by

authorizing safe passage through track sections.

• In a track circuit, what component detects the presence of a train?
• Transformer
• Axle shunt 1 / 4

• Relay coil
• Capacitor

Rationale: Train wheels and axles short the rails, creating a shunt that drops

relay voltage and signals track occupancy.

• What voltage is typically used in a DC track circuit?

A. 120 V DC

B. 12 V DC

C. 48 V AC

D. 240 V DC

Rationale: Low-voltage DC circuits (around 12 V) minimize shock risk and

interference.

• What does an interlocking system prevent?
• Power surges
• Conflicting train routes
• Broken rails
• Train delays

Rationale: Interlocking ensures signals and switches are set to prevent train

movements that would conflict.

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5. A red aspect on a color light signal means:

• Stop
• Proceed
• Approach
• Clear

Rationale: Red universally means stop and do not proceed until cleared.

• What device converts AC to DC for signal equipment?
• Rectifier
• Inverter
• Regulator
• Transformer

Rationale: A rectifier allows DC operation from AC supply sources.

• What is the standard gauge distance between rails in most systems?
• 1435 mm (4 ft 8½ in)
• 1500 mm
• 1000 mm
• 1600 mm

Rationale: The standard gauge globally is 1435 mm for interoperability.

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• What is a relay used for in signal circuits?
• Filtering noise
• Electrically isolating and controlling circuits
• Generating power
• Measuring voltage

Rationale: Relays switch high-current circuits using low-current control

signals.

• What component ensures time delay in signal relay logic?
• Diode
• Timer relay
• Transformer
• Shunt resistor

Rationale: Timer relays introduce controlled delay for safety sequencing.

10. A yellow signal aspect usually indicates:

• Stop
• Clear
• Caution / Prepare to stop
• Restricted

Rationale: Yellow warns the train to prepare to stop at the next signal.

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