Electrical & Mechanical Fundamentals Flashcards
7 cards from real CPT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Electrical & Mechanical Fundamentals flashcards as text
Which lubrication method delivers a metered, continuous supply of oil to bearings during machine operation?
Answer: Centralized oil mist system
A centralized oil mist system atomizes oil and delivers it continuously through distribution lines to multiple bearing points simultaneously.
What electrical safety device automatically opens a circuit when current exceeds a predetermined level and must be manually reset?
Answer: Circuit breaker
A circuit breaker trips (opens) on overcurrent and can be manually reset after the fault is cleared, unlike a fuse which must be replaced.
In mechanical power transmission, what is 'backlash' in a gear set?
Answer: The clearance between mating gear teeth
Backlash is the play or clearance between meshing gear teeth, necessary to allow for lubrication and thermal expansion but excessive backlash causes noise and inaccuracy.
A three-phase motor has its rotation reversed by:
Answer: Swapping any two of the three power leads
Swapping any two of the three phase conductors reverses the phase sequence, which reverses the direction of the motor's rotating magnetic field and shaft rotation.
What is the function of a pneumatic FRL unit (Filter-Regulator-Lubricator) in a compressed air system?
Answer: Condition air by removing moisture/contaminants, regulating pressure, and adding lubrication
An FRL unit conditions compressed air by filtering out particles and moisture, regulating pressure to the required level, and adding a fine oil mist for tool/actuator lubrication.
What type of coupling is used to connect two shafts that may have slight angular or parallel misalignment?
Answer: Flexible jaw coupling
Flexible jaw (spider) couplings accommodate minor angular and parallel misalignment through a resilient elastomeric insert, reducing vibration transmission.
Which electrical wiring color is designated as the equipment grounding conductor in US NEC standards?
Answer: Green or bare copper
Per the NEC, green insulation or bare copper wire designates the equipment grounding conductor (EGC) which provides a fault current return path to protect personnel.