Basic Electrical Principles Flashcards

What does the acronym 'EMF' stand for in electrical engineering?

Answer: Electromotive Force

EMF stands for Electromotive Force, which is the energy per unit charge supplied by a source like a battery or generator.

A motor nameplate shows 240V, 10A. What is the motor's power rating?

Answer: 2400 W

Power = V × I = 240 × 10 = 2400 W (2.4 kW).

What is the purpose of a circuit breaker compared to a fuse?

Answer: A circuit breaker can be reset after tripping; a fuse must be replaced

A circuit breaker is a resettable protective device, while a fuse is a one-time-use device that must be replaced after it blows.

In a three-phase power system, what is the phase difference between each voltage waveform?

Answer: 120 degrees

In a balanced three-phase system, the three voltage waveforms are evenly spaced 120 degrees apart.

What happens to current in a series circuit if one component fails (opens)?

Answer: Current flow stops completely

In a series circuit, all components share the same single path, so an open in any component stops all current flow.

What is the primary function of an inductor in an electrical circuit?

Answer: Store energy in a magnetic field and oppose changes in current

An inductor stores energy in a magnetic field and resists changes in current flow through it.

Which law states that the total current entering a junction equals the total current leaving it?

Answer: Kirchhoff's Current Law

Kirchhoff's Current Law (KCL) states that the algebraic sum of currents at any node in a circuit is zero.