WTMA Basic Electrical Principles 2 — Questions and Answers
Question 1: A wire carries 3 amperes of current for 10 seconds. How many coulombs of charge passed through the wire?
- 30 coulombs (Correct answer)
- 3 coulombs
- 10 coulombs
- 0.3 coulombs
Correct answer: 30 coulombs
Charge (Q) = Current (I) × Time (t), so Q = 3 A × 10 s = 30 coulombs.
Question 2: Which material is the BEST conductor of electricity?
- Copper (Correct answer)
- Rubber
- Glass
- Wood
Correct answer: Copper
Copper has very low electrical resistance and is one of the best practical conductors used in wiring.
Question 3: If voltage across a resistor doubles while resistance stays the same, what happens to the current?
- It doubles (Correct answer)
- It halves
- It stays the same
- It quadruples
Correct answer: It doubles
By Ohm's Law (I = V/R), doubling V while R stays constant doubles the current.
Question 4: What does a fuse do in an electrical circuit?
- Breaks the circuit when current is too high (Correct answer)
- Increases voltage
- Stores electrical energy
- Reduces resistance
Correct answer: Breaks the circuit when current is too high
A fuse contains a wire that melts and breaks the circuit when current exceeds a safe level, preventing damage.
Question 5: Two resistors of 6 ohms each are connected in series. What is the total resistance?
- 12 ohms (Correct answer)
- 3 ohms
- 6 ohms
- 36 ohms
Correct answer: 12 ohms
In a series circuit, total resistance is the sum of all resistors: 6 + 6 = 12 ohms.
Question 6: Which unit measures electrical power?
- Watt (Correct answer)
- Ohm
- Ampere
- Volt
Correct answer: Watt
Power is measured in watts (W), where 1 watt equals 1 volt multiplied by 1 ampere.
Question 7: In a parallel circuit with two identical bulbs, if one bulb burns out, what happens to the other?
- It continues to glow normally (Correct answer)
- It goes out too
- It glows brighter
- It glows dimmer
Correct answer: It continues to glow normally
In a parallel circuit, each branch is independent, so the remaining bulb continues to receive full voltage.
WTMA Basic Electrical Principles 2
A wire carries 3 amperes of current for 10 seconds.
How many coulombs of charge passed through the wire?