Bennett Mechanical Test Electricity and Circuits 2 โ Questions and Answers
Question 1: In a series circuit with three identical light bulbs, what happens to the others if one bulb burns out?
- They glow brighter
- They go out (Correct answer)
- They stay the same
- They flicker on and off
Correct answer: They go out
A series circuit has one path, so a break at any bulb stops current to all.
Question 2: What is the unit of electrical resistance?
- Volt
- Ampere
- Ohm (Correct answer)
- Watt
Correct answer: Ohm
Resistance is measured in ohms, symbolized by the Greek letter omega.
Question 3: Using Ohm's law, what current flows through a 10-ohm resistor connected to a 20-volt source?
- 0.5 amps
- 2 amps (Correct answer)
- 10 amps
- 200 amps
Correct answer: 2 amps
Current equals voltage divided by resistance, so 20 V รท 10 ฮฉ = 2 A.
Question 4: Which material is the best conductor of electricity?
- Rubber
- Copper (Correct answer)
- Glass
- Wood
Correct answer: Copper
Copper has many free electrons, making it an excellent conductor used in wiring.
Question 5: In a parallel circuit, how does the voltage across each branch compare?
- It is divided equally
- It is the same across each branch (Correct answer)
- It increases with more branches
- It is zero in every branch
Correct answer: It is the same across each branch
Each branch of a parallel circuit receives the full source voltage.
Question 6: What device protects a circuit by breaking the connection when current is too high?
- Capacitor
- Transformer
- Fuse (Correct answer)
- Resistor
Correct answer: Fuse
A fuse melts and opens the circuit when excessive current flows, preventing damage.
Question 7: What does a battery provide to a circuit?
- Resistance
- Voltage (electromotive force) (Correct answer)
- Magnetism only
- Insulation
Correct answer: Voltage (electromotive force)
A battery supplies the voltage that pushes current through a circuit.
Bennett Mechanical Test Electricity and Circuits 2
In a series circuit with three identical light bulbs, what happens to the others if one bulb burns out?