OAR Mechanical Comprehension: Electricity Questions and Answers Flashcards
6 cards from real OAR practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 OAR Mechanical Comprehension: Electricity Questions and Answers flashcards as text
What is the total resistance of a 6-ohm and a 3-ohm resistor connected in parallel?
Answer: 2 ohms
Using the parallel formula (1/Rt = 1/R1 + 1/R2), 1/6 + 1/3 = 1/2, so Rt equals 2 ohms.
Which component opposes changes in current flow in a circuit?
Answer: Inductor
An inductor opposes changes in current by generating a back-EMF proportional to the rate of current change.
If the voltage across a circuit is doubled while resistance stays the same, what happens to the current?
Answer: It doubles
According to Ohm's law (I = V/R), doubling the voltage with constant resistance doubles the current.
What does a fuse do in an electrical circuit?
Answer: Breaks the circuit when current exceeds a safe level
A fuse contains a metal wire that melts and breaks the circuit when current exceeds its rated value.
In a DC circuit, electrons flow from which terminal to which?
Answer: Negative to positive
Electrons carry negative charge and are attracted toward the positive terminal, flowing from negative to positive.
What is the power dissipated by a 10-ohm resistor carrying 2 amperes of current?
Answer: 40 W
Using P = I²R, power equals 2² times 10, which is 40 watts.