IEC YEAR 1 FINAL EXAM
COMPREHENSIVE PRACTICE (2026/2027 EDITION)
150 Multiple-Choice Questions - Complete Practice Exam
Independent-Study Disclaimer
This practice exam is an independent study aid and is not affiliated with, endorsed by, or sponsored by the
Independent Electrical Contractors (IEC), the National Electrical Code, NFPA, or any other organization. It is
provided for educational and self-assessment purposes only and is not a substitute for official IEC coursework,
apprenticeship requirements, or current code references. Code and curriculum content are subject to change;
always verify against the current NEC and your program.
, Section 1: DC Theory - Ohm's Law, Series, Parallel, Combination Circuits,
Power (30 questions)
Q1: Ohm's Law states that voltage (E) equals:
A. Power divided by current
B. Resistance divided by current
C. Current times time
D. Current times resistance (E = I × R) [CORRECT]
Correct Answer: D
Rationale: Ohm's Law is E = I × R, where voltage equals current times resistance. The other options do not
state Ohm's Law.
Q2: The power equation for a DC circuit is:
A. P = E / I
B. P = R / I
C. P = E × I [CORRECT]
D. P = I / E
Correct Answer: C
Rationale: Power equals voltage times current (P = E × I). The other equations are not the power formula.
Q3: If a DC circuit has 120 V and a resistance of 30 ohms, the current is:
A. 3600 A
B. 4 A [CORRECT]
C. 0.25 A
D. 90 A
Correct Answer: B
Rationale: I = E / R = = 4 A. The other values are incorrect.
Q4: If a circuit draws 5 A at 120 V, the power is:
A. 24 W
B. 600 W [CORRECT]
C. 120 W
D. 6 W
Correct Answer: B
Rationale: P = E × I = 120 × 5 = 600 W. The other values are incorrect.
Q5: In a series circuit, the current is:
A. The same at every point in the circuit [CORRECT]
B. Different at each component
C. Zero
D. Equal to the voltage
Correct Answer: A
Rationale: Series circuits have the same current at every point. Voltage is divided, but current is constant.
IEC Year 1 Final Exam - 2026/2027 Edition Page 2
, Q6: The total resistance of resistors in series is:
A. Less than the smallest resistance
B. The sum of all resistances [CORRECT]
C. The reciprocal of the sum
D. Equal to the largest resistance only
Correct Answer: B
Rationale: Series resistances add to give the total. The other options describe parallel resistance.
Q7: In a series circuit, the sum of the voltage drops across each resistor equals:
A. The source voltage [CORRECT]
B. Zero
C. The total current
D. The total resistance
Correct Answer: A
Rationale: Kirchhoff's Voltage Law states the sum of voltage drops equals the source voltage. The other
options are incorrect.
Q8: In a parallel circuit, the total resistance is:
A. Greater than the largest branch resistance
B. Equal to the sum of branches
C. Always zero
D. Less than the smallest branch resistance [CORRECT]
Correct Answer: D
Rationale: The total resistance of a parallel circuit is less than the smallest branch resistance. The other
options are incorrect.
Q9: The total resistance of two 20-ohm resistors in parallel is:
A. 40 ohms
B. 20 ohms
C. 10 ohms [CORRECT]
D. 0.1 ohm
Correct Answer: C
Rationale: Two equal parallel resistors give half the value, so 20/2 = 10 ohms. The other values are
incorrect.
Q10: In a parallel circuit, the total current is:
A. Equal to one branch current
B. Always zero
C. The sum of the branch currents [CORRECT]
D. The voltage times resistance
Correct Answer: C
Rationale: Kirchhoff's Current Law states total current equals the sum of branch currents. The other options
are incorrect.
IEC Year 1 Final Exam - 2026/2027 Edition Page 3
, Q11: In a parallel circuit, the voltage across each branch is:
A. Equal to the source voltage [CORRECT]
B. Divided among branches
C. Zero
D. The sum of the currents
Correct Answer: A
Rationale: In parallel, each branch has the full source voltage. The other options describe series behavior.
Q12: A combination (series-parallel) circuit is reduced by first:
A. Simplifying parallel groups into equivalent resistances, then combining series parts [CORRECT]
B. Adding all resistances as series
C. Ignoring the parallel parts
D. Removing all resistors
Correct Answer: A
Rationale: To solve combination circuits, simplify parallel branches into equivalents and then combine series
parts. The other options are incorrect.
Q13: Kirchhoff's Current Law states that the sum of currents entering a junction equals:
A. Zero
B. The voltage at the junction
C. The sum of currents leaving the junction [CORRECT]
D. The total resistance
Correct Answer: C
Rationale: Kirchhoff's Current Law: current entering a junction equals current leaving it. The other options
are incorrect.
Q14: Kirchhoff's Voltage Law states that the algebraic sum of the voltage rises and drops around a closed loop
is:
A. Equal to the current
B. Equal to the resistance
C. Infinite
D. Zero [CORRECT]
Correct Answer: D
Rationale: Kirchhoff's Voltage Law: the algebraic sum of voltage rises and drops around a loop is zero. The
other options are incorrect.
Q15: Which of the following is an example of a metric prefix meaning one thousandth (0.001)?
A. Kilo-
B. Milli- [CORRECT]
C. Mega-
D. Giga-
Correct Answer: B
Rationale: Milli- means one thousandth (10^-3). Kilo- is a thousand, mega- is a million, and giga- is a billion.
IEC Year 1 Final Exam - 2026/2027 Edition Page 4
COMPREHENSIVE PRACTICE (2026/2027 EDITION)
150 Multiple-Choice Questions - Complete Practice Exam
Independent-Study Disclaimer
This practice exam is an independent study aid and is not affiliated with, endorsed by, or sponsored by the
Independent Electrical Contractors (IEC), the National Electrical Code, NFPA, or any other organization. It is
provided for educational and self-assessment purposes only and is not a substitute for official IEC coursework,
apprenticeship requirements, or current code references. Code and curriculum content are subject to change;
always verify against the current NEC and your program.
, Section 1: DC Theory - Ohm's Law, Series, Parallel, Combination Circuits,
Power (30 questions)
Q1: Ohm's Law states that voltage (E) equals:
A. Power divided by current
B. Resistance divided by current
C. Current times time
D. Current times resistance (E = I × R) [CORRECT]
Correct Answer: D
Rationale: Ohm's Law is E = I × R, where voltage equals current times resistance. The other options do not
state Ohm's Law.
Q2: The power equation for a DC circuit is:
A. P = E / I
B. P = R / I
C. P = E × I [CORRECT]
D. P = I / E
Correct Answer: C
Rationale: Power equals voltage times current (P = E × I). The other equations are not the power formula.
Q3: If a DC circuit has 120 V and a resistance of 30 ohms, the current is:
A. 3600 A
B. 4 A [CORRECT]
C. 0.25 A
D. 90 A
Correct Answer: B
Rationale: I = E / R = = 4 A. The other values are incorrect.
Q4: If a circuit draws 5 A at 120 V, the power is:
A. 24 W
B. 600 W [CORRECT]
C. 120 W
D. 6 W
Correct Answer: B
Rationale: P = E × I = 120 × 5 = 600 W. The other values are incorrect.
Q5: In a series circuit, the current is:
A. The same at every point in the circuit [CORRECT]
B. Different at each component
C. Zero
D. Equal to the voltage
Correct Answer: A
Rationale: Series circuits have the same current at every point. Voltage is divided, but current is constant.
IEC Year 1 Final Exam - 2026/2027 Edition Page 2
, Q6: The total resistance of resistors in series is:
A. Less than the smallest resistance
B. The sum of all resistances [CORRECT]
C. The reciprocal of the sum
D. Equal to the largest resistance only
Correct Answer: B
Rationale: Series resistances add to give the total. The other options describe parallel resistance.
Q7: In a series circuit, the sum of the voltage drops across each resistor equals:
A. The source voltage [CORRECT]
B. Zero
C. The total current
D. The total resistance
Correct Answer: A
Rationale: Kirchhoff's Voltage Law states the sum of voltage drops equals the source voltage. The other
options are incorrect.
Q8: In a parallel circuit, the total resistance is:
A. Greater than the largest branch resistance
B. Equal to the sum of branches
C. Always zero
D. Less than the smallest branch resistance [CORRECT]
Correct Answer: D
Rationale: The total resistance of a parallel circuit is less than the smallest branch resistance. The other
options are incorrect.
Q9: The total resistance of two 20-ohm resistors in parallel is:
A. 40 ohms
B. 20 ohms
C. 10 ohms [CORRECT]
D. 0.1 ohm
Correct Answer: C
Rationale: Two equal parallel resistors give half the value, so 20/2 = 10 ohms. The other values are
incorrect.
Q10: In a parallel circuit, the total current is:
A. Equal to one branch current
B. Always zero
C. The sum of the branch currents [CORRECT]
D. The voltage times resistance
Correct Answer: C
Rationale: Kirchhoff's Current Law states total current equals the sum of branch currents. The other options
are incorrect.
IEC Year 1 Final Exam - 2026/2027 Edition Page 3
, Q11: In a parallel circuit, the voltage across each branch is:
A. Equal to the source voltage [CORRECT]
B. Divided among branches
C. Zero
D. The sum of the currents
Correct Answer: A
Rationale: In parallel, each branch has the full source voltage. The other options describe series behavior.
Q12: A combination (series-parallel) circuit is reduced by first:
A. Simplifying parallel groups into equivalent resistances, then combining series parts [CORRECT]
B. Adding all resistances as series
C. Ignoring the parallel parts
D. Removing all resistors
Correct Answer: A
Rationale: To solve combination circuits, simplify parallel branches into equivalents and then combine series
parts. The other options are incorrect.
Q13: Kirchhoff's Current Law states that the sum of currents entering a junction equals:
A. Zero
B. The voltage at the junction
C. The sum of currents leaving the junction [CORRECT]
D. The total resistance
Correct Answer: C
Rationale: Kirchhoff's Current Law: current entering a junction equals current leaving it. The other options
are incorrect.
Q14: Kirchhoff's Voltage Law states that the algebraic sum of the voltage rises and drops around a closed loop
is:
A. Equal to the current
B. Equal to the resistance
C. Infinite
D. Zero [CORRECT]
Correct Answer: D
Rationale: Kirchhoff's Voltage Law: the algebraic sum of voltage rises and drops around a loop is zero. The
other options are incorrect.
Q15: Which of the following is an example of a metric prefix meaning one thousandth (0.001)?
A. Kilo-
B. Milli- [CORRECT]
C. Mega-
D. Giga-
Correct Answer: B
Rationale: Milli- means one thousandth (10^-3). Kilo- is a thousand, mega- is a million, and giga- is a billion.
IEC Year 1 Final Exam - 2026/2027 Edition Page 4
