OAR OAR Mechanical Comprehension: Electricity Questions and Answers 3 ā Questions and Answers
Question 1: What is the total resistance of a 6-ohm and a 3-ohm resistor connected in parallel?
- 2 ohms (Correct answer)
- 9 ohms
- 4.5 ohms
- 3 ohms
Correct answer: 2 ohms
Using the parallel formula (1/Rt = 1/R1 + 1/R2), 1/6 + 1/3 = 1/2, so Rt equals 2 ohms.
Question 2: Which component opposes changes in current flow in a circuit?
- Inductor (Correct answer)
- Capacitor
- Resistor
- Diode
Correct answer: Inductor
An inductor opposes changes in current by generating a back-EMF proportional to the rate of current change.
Question 3: If the voltage across a circuit is doubled while resistance stays the same, what happens to the current?
- It doubles (Correct answer)
- It halves
- It quadruples
- It stays the same
Correct answer: It doubles
According to Ohm's law (I = V/R), doubling the voltage with constant resistance doubles the current.
Question 4: What does a fuse do in an electrical circuit?
- Breaks the circuit when current exceeds a safe level (Correct answer)
- Increases voltage output
- Stores excess electrical charge
- Converts AC to DC
Correct 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.
Question 5: In a DC circuit, electrons flow from which terminal to which?
- Negative to positive (Correct answer)
- Positive to negative
- They alternate direction
- They do not move
Correct answer: Negative to positive
Electrons carry negative charge and are attracted toward the positive terminal, flowing from negative to positive.
Question 6: What is the power dissipated by a 10-ohm resistor carrying 2 amperes of current?
- 40 W (Correct answer)
- 20 W
- 5 W
- 100 W
Correct answer: 40 W
Using P = IĀ²R, power equals 2Ā² times 10, which is 40 watts.
OAR OAR Mechanical Comprehension: Electricity Questions and Answers 3
What is the total resistance of a 6-ohm and a 3-ohm resistor connected in parallel?