LEC Study Guide 2026
Everything you need to pass the LEC exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.
📋 LEC Exam Format at a Glance
📚 LEC Topics to Study (63)
✍️ Sample LEC Questions & Answers
1. On an AC traction locomotive, what advantage does it have over DC traction on steep grades?
AC traction motors can sustain higher continuous tractive effort at very low speeds without overheating, making them superior to DC motors on steep ruling grades.
2. Which condition would cause a 'sticking brake' on a freight car?
A broken release spring in the brake cylinder prevents the piston from returning, leaving brakes applied even after the brake pipe is recharged.
3. A locomotive's air compressor fails to build pressure. Which system is most immediately affected?
The automatic and independent brake systems rely on compressed air; without adequate pressure, brakes cannot be applied or released properly.
4. A locomotive engineer reports that the exhaust stack is emitting white smoke during cold startup. What is the most likely cause?
White smoke during cold startup is typically water vapor condensing and unburned fuel misting as the engine and exhaust system reach operating temperature.
5. A locomotive engineer must report which of the following conditions to the proper authority before operating the locomotive?
FRA regulations require engineers to self-disclose any physical or mental impairment that could affect safe locomotive operation.
6. A locomotive's truck is said to have 'rock and roll' motion. What does this describe?
Rock and roll refers to simultaneous lateral (rocking) and rotational (rolling) oscillation of the locomotive body on its suspension.