Polytechnic Electronics and Electrical Engineering 2

Question 1

What does AC stand for in electrical engineering?

Accepted Answer

Alternating Current

Answer

AC stands for Alternating Current, where the direction of current flow reverses periodically.

Question 2

Kirchhoff's Current Law (KCL) states that:

Accepted Answer

The sum of currents entering a node equals the sum leaving it

Answer

KCL states that the algebraic sum of all currents at a node is zero, meaning current in equals current out.

Question 3

What is the capacitance of a capacitor that stores 0.01 coulombs of charge at 5 volts?

Accepted Answer

0.002 F

Answer

C = Q/V = 0.01/5 = 0.002 F (2 millifarads), using the capacitance formula.

Question 4

An NPN transistor is in saturation mode when:

Accepted Answer

Both junctions are forward-biased

Answer

In saturation, both the base-emitter and base-collector junctions are forward-biased, fully turning on the transistor.

Question 5

What is the purpose of a voltage divider circuit?

Accepted Answer

To produce a lower output voltage from a higher input voltage

Answer

A voltage divider uses two resistors in series to produce an output voltage that is a fraction of the input voltage.

Polytechnic Practice Test