Electrical Systems 1 – SACA 2026/2027 Certification Practice
Examination with correct answers and rationales
1. What is the unit of electrical current?
A. Volt
B. Ampere (Amp)
C. Ohm
D. Watt
Correct Answer: B. Ampere (Amp)
Rationale: Current is the flow of electric charge and is measured in amperes (A).
2. Voltage is defined as:
A. The resistance to current flow
B. Electrical pressure that pushes electrons through a circuit
C. Electrical power consumed
D. The amount of heat produced
Correct Answer: B
Rationale: Voltage (V) is the electrical potential difference that causes current to flow.
3. Which instrument measures voltage?
A. Ammeter
B. Voltmeter
C. Ohmmeter
D. Clamp meter (current only)
Correct Answer: B
Rationale: A voltmeter is connected in parallel with a circuit component to measure voltage.
4. Resistance is measured in:
,A. Watts
B. Volts
C. Ohms
D. Amperes
Correct Answer: C
Rationale: Resistance is measured in ohms (Ω).
5. According to Ohm's Law, current equals:
A. V × R
B. V ÷ R
C. R ÷ V
D. P × I
Correct Answer: B
Rationale: Ohm's Law states that I = V/R.
6. Which formula calculates electrical power?
A. P = V × I
B. P = R ÷ I
C. P = I ÷ V
D. P = R × V
Correct Answer: A
Rationale: Electrical power equals voltage multiplied by current.
7. A fuse is designed to:
A. Increase voltage
B. Protect a circuit from overcurrent
C. Store electrical energy
D. Reduce resistance
Correct Answer: B
, Rationale: A fuse melts when current exceeds its rated value, protecting equipment.
8. What is the primary purpose of a circuit breaker?
A. Increase current flow
B. Protect electrical circuits by interrupting excessive current
C. Reduce voltage
D. Measure resistance
Correct Answer: B
Rationale: Circuit breakers automatically disconnect a circuit during overloads or short circuits.
9. Which material is considered an electrical insulator?
A. Copper
B. Aluminum
C. Rubber
D. Silver
Correct Answer: C
Rationale: Rubber resists the flow of electricity and is commonly used as insulation.
10. Which material is an excellent electrical conductor?
A. Glass
B. Plastic
C. Copper
D. Wood
Correct Answer: C
Rationale: Copper has low resistance and is widely used for electrical wiring.
11. What does AC stand for?
Examination with correct answers and rationales
1. What is the unit of electrical current?
A. Volt
B. Ampere (Amp)
C. Ohm
D. Watt
Correct Answer: B. Ampere (Amp)
Rationale: Current is the flow of electric charge and is measured in amperes (A).
2. Voltage is defined as:
A. The resistance to current flow
B. Electrical pressure that pushes electrons through a circuit
C. Electrical power consumed
D. The amount of heat produced
Correct Answer: B
Rationale: Voltage (V) is the electrical potential difference that causes current to flow.
3. Which instrument measures voltage?
A. Ammeter
B. Voltmeter
C. Ohmmeter
D. Clamp meter (current only)
Correct Answer: B
Rationale: A voltmeter is connected in parallel with a circuit component to measure voltage.
4. Resistance is measured in:
,A. Watts
B. Volts
C. Ohms
D. Amperes
Correct Answer: C
Rationale: Resistance is measured in ohms (Ω).
5. According to Ohm's Law, current equals:
A. V × R
B. V ÷ R
C. R ÷ V
D. P × I
Correct Answer: B
Rationale: Ohm's Law states that I = V/R.
6. Which formula calculates electrical power?
A. P = V × I
B. P = R ÷ I
C. P = I ÷ V
D. P = R × V
Correct Answer: A
Rationale: Electrical power equals voltage multiplied by current.
7. A fuse is designed to:
A. Increase voltage
B. Protect a circuit from overcurrent
C. Store electrical energy
D. Reduce resistance
Correct Answer: B
, Rationale: A fuse melts when current exceeds its rated value, protecting equipment.
8. What is the primary purpose of a circuit breaker?
A. Increase current flow
B. Protect electrical circuits by interrupting excessive current
C. Reduce voltage
D. Measure resistance
Correct Answer: B
Rationale: Circuit breakers automatically disconnect a circuit during overloads or short circuits.
9. Which material is considered an electrical insulator?
A. Copper
B. Aluminum
C. Rubber
D. Silver
Correct Answer: C
Rationale: Rubber resists the flow of electricity and is commonly used as insulation.
10. Which material is an excellent electrical conductor?
A. Glass
B. Plastic
C. Copper
D. Wood
Correct Answer: C
Rationale: Copper has low resistance and is widely used for electrical wiring.
11. What does AC stand for?
