Electrical Contractor Exam Newest 2026/2027 Questions and
Correct Detailed Answers with Rationales Already Graded A+
1. What is the basic unit of electrical current?
A. Volt
B. Ohm
C. Ampere
D. Watt
Correct Answer: C. Ampere
Rationale: The ampere (A) is the unit used to measure electrical current, or the
rate at which electric charge flows through a circuit.
2. Which formula represents Ohm's Law?
A. E = I × R
,B. P = E + I
C. R = E × I
D. I = P × R
Correct Answer: A. E = I × R
Rationale: Ohm's Law states that voltage (E) equals current (I) multiplied by
resistance (R). This relationship is fundamental for calculating voltage, current,
and resistance.
3. A 120-volt circuit has a resistance of 20 ohms. What current flows?
A. 2 A
B. 4 A
C. 6 A
D. 10 A
Correct Answer: C. 6 A
Rationale: Using I = E ÷ R: 120 V ÷ 20 Ω = 6 A.
,4. What is the unit of electrical resistance?
A. Watt
B. Ohm
C. Volt
D. Ampere
Correct Answer: B. Ohm
Rationale: Resistance is measured in ohms (Ω). Resistance opposes the flow of
electrical current.
5. What is the unit of electrical power?
A. Watt
B. Ampere
C. Ohm
D. Coulomb
, Correct Answer: A. Watt
Rationale: Electrical power is measured in watts. A common formula is P = E × I.
6. A 240-volt load draws 10 amperes. What is its approximate power?
A. 240 W
B. 1,200 W
C. 2,400 W
D. 24,000 W
Correct Answer: C. 2,400 W
Rationale: P = E × I = 240 × 10 = 2,400 watts.
7. What generally happens to current when resistance increases while voltage
remains constant?
Correct Detailed Answers with Rationales Already Graded A+
1. What is the basic unit of electrical current?
A. Volt
B. Ohm
C. Ampere
D. Watt
Correct Answer: C. Ampere
Rationale: The ampere (A) is the unit used to measure electrical current, or the
rate at which electric charge flows through a circuit.
2. Which formula represents Ohm's Law?
A. E = I × R
,B. P = E + I
C. R = E × I
D. I = P × R
Correct Answer: A. E = I × R
Rationale: Ohm's Law states that voltage (E) equals current (I) multiplied by
resistance (R). This relationship is fundamental for calculating voltage, current,
and resistance.
3. A 120-volt circuit has a resistance of 20 ohms. What current flows?
A. 2 A
B. 4 A
C. 6 A
D. 10 A
Correct Answer: C. 6 A
Rationale: Using I = E ÷ R: 120 V ÷ 20 Ω = 6 A.
,4. What is the unit of electrical resistance?
A. Watt
B. Ohm
C. Volt
D. Ampere
Correct Answer: B. Ohm
Rationale: Resistance is measured in ohms (Ω). Resistance opposes the flow of
electrical current.
5. What is the unit of electrical power?
A. Watt
B. Ampere
C. Ohm
D. Coulomb
, Correct Answer: A. Watt
Rationale: Electrical power is measured in watts. A common formula is P = E × I.
6. A 240-volt load draws 10 amperes. What is its approximate power?
A. 240 W
B. 1,200 W
C. 2,400 W
D. 24,000 W
Correct Answer: C. 2,400 W
Rationale: P = E × I = 240 × 10 = 2,400 watts.
7. What generally happens to current when resistance increases while voltage
remains constant?
