CFESA ELECTRICAL CERTIFICATION EXAM
1. According to Ohm's Law, if voltage increases while resistance stays constant,
what happens to current?
A. Increases
B. Decreases
C. Stays the same
D. Drops to zero
Correct Answer: A — Increases
Rationale: Ohm's Law states I = V / R. With resistance constant, current is directly
proportional to voltage, so current increases.
2. What is the formula for electrical power?
A. P = I R
B. P = V I
C. P = V / I
D. P = I / V
Correct Answer: B — P = V I
Rationale: Electrical power equals voltage multiplied by current (P = VI), also
expressible as P = I²R or P = V²/R.
3. A circuit has 120V and draws 10A. What is the resistance?
A. 1200 Ω
B. 12 Ω
C. 0.083 Ω
D. 120 Ω
Correct Answer: B — 12 Ω
Rationale: Using R = V / I = = 12 Ω.
,4. What is the unit of electrical resistance?
A. Watt
B. Ampere
C. Ohm
D. Volt
Correct Answer: C — Ohm
Rationale: Resistance is measured in ohms (Ω), named after Georg Ohm.
5. In a series circuit, total resistance is:
A. The sum of all resistances
B. The reciprocal of the sum of reciprocals
C. Always less than the smallest resistor
D. Equal to the largest resistor only
Correct Answer: A — The sum of all resistances
Rationale: In series circuits, resistances add directly: R_total = R1 + R2 + R3 + ...
6. In a parallel circuit, total current is:
A. The same through each branch
B. The sum of the branch currents
C. Always zero
D. Equal to voltage divided by number of branches
Correct Answer: B — The sum of the branch currents
Rationale: In parallel circuits, total current supplied by the source equals the sum of the
currents through each branch.
7. What happens to total resistance when resistors are added in parallel?
A. Increases
B. Decreases
C. Stays the same
D. Becomes infinite
Correct Answer: B — Decreases
Rationale: Adding parallel paths gives current more routes to flow, so total resistance
always decreases below the smallest branch resistance.
,8. A heating element rated 1000W operates at 120V. What current does it draw?
A. 8.33 A
B. 12 A
C. 120 A
D. 1 A
Correct Answer: A — 8.33 A
Rationale: Using I = P / V = = 8.33 A.
9. Which law states that current entering a junction equals current leaving it?
A. Ohm's Law
B. Kirchhoff's Current Law
C. Kirchhoff's Voltage Law
D. Watt's Law
Correct Answer: B — Kirchhoff's Current Law
Rationale: Kirchhoff's Current Law (KCL) is based on conservation of charge: current in
equals current out at any node.
10. Which law states the sum of voltage drops in a closed loop equals the source
voltage?
A. Kirchhoff's Current Law
B. Ohm's Law
C. Kirchhoff's Voltage Law
D. Lenz's Law
Correct Answer: C — Kirchhoff's Voltage Law
Rationale: Kirchhoff's Voltage Law (KVL) states the algebraic sum of voltage rises and
drops around a closed loop equals zero.
11. What does a fuse do in a circuit?
A. Increases voltage
B. Protects the circuit from overcurrent by melting/opening
C. Steps down voltage
D. Stores electrical charge
Correct Answer: B — Protects the circuit from overcurrent by melting/opening
Rationale: A fuse contains an element that melts and opens the circuit when current
exceeds its rated value, protecting wiring and components.
, 12. An open circuit has:
A. Zero resistance
B. Infinite resistance
C. Continuous current flow
D. A short circuit condition
Correct Answer: B — Infinite resistance
Rationale: An open circuit has a break in the current path, so resistance measured
across the break is effectively infinite and no current flows.
13. A short circuit is characterized by:
A. Abnormally high resistance
B. Abnormally low resistance, causing excess current
C. No current flow
D. Balanced voltage
Correct Answer: B — Abnormally low resistance, causing excess current
Rationale: A short circuit provides an unintended low-resistance path, causing current
to rise dramatically, often tripping breakers or blowing fuses.
14. The unit of electrical charge is:
A. Ampere
B. Coulomb
C. Farad
D. Henry
Correct Answer: B — Coulomb
Rationale: Electrical charge is measured in coulombs; one ampere equals one
coulomb of charge passing a point per second.
15. One ampere equals:
A. One volt per ohm
B. One coulomb per second
C. One watt per volt
D. One joule per second
Correct Answer: B — One coulomb per second
Rationale: By definition, one ampere is the flow of one coulomb of charge per second.
1. According to Ohm's Law, if voltage increases while resistance stays constant,
what happens to current?
A. Increases
B. Decreases
C. Stays the same
D. Drops to zero
Correct Answer: A — Increases
Rationale: Ohm's Law states I = V / R. With resistance constant, current is directly
proportional to voltage, so current increases.
2. What is the formula for electrical power?
A. P = I R
B. P = V I
C. P = V / I
D. P = I / V
Correct Answer: B — P = V I
Rationale: Electrical power equals voltage multiplied by current (P = VI), also
expressible as P = I²R or P = V²/R.
3. A circuit has 120V and draws 10A. What is the resistance?
A. 1200 Ω
B. 12 Ω
C. 0.083 Ω
D. 120 Ω
Correct Answer: B — 12 Ω
Rationale: Using R = V / I = = 12 Ω.
,4. What is the unit of electrical resistance?
A. Watt
B. Ampere
C. Ohm
D. Volt
Correct Answer: C — Ohm
Rationale: Resistance is measured in ohms (Ω), named after Georg Ohm.
5. In a series circuit, total resistance is:
A. The sum of all resistances
B. The reciprocal of the sum of reciprocals
C. Always less than the smallest resistor
D. Equal to the largest resistor only
Correct Answer: A — The sum of all resistances
Rationale: In series circuits, resistances add directly: R_total = R1 + R2 + R3 + ...
6. In a parallel circuit, total current is:
A. The same through each branch
B. The sum of the branch currents
C. Always zero
D. Equal to voltage divided by number of branches
Correct Answer: B — The sum of the branch currents
Rationale: In parallel circuits, total current supplied by the source equals the sum of the
currents through each branch.
7. What happens to total resistance when resistors are added in parallel?
A. Increases
B. Decreases
C. Stays the same
D. Becomes infinite
Correct Answer: B — Decreases
Rationale: Adding parallel paths gives current more routes to flow, so total resistance
always decreases below the smallest branch resistance.
,8. A heating element rated 1000W operates at 120V. What current does it draw?
A. 8.33 A
B. 12 A
C. 120 A
D. 1 A
Correct Answer: A — 8.33 A
Rationale: Using I = P / V = = 8.33 A.
9. Which law states that current entering a junction equals current leaving it?
A. Ohm's Law
B. Kirchhoff's Current Law
C. Kirchhoff's Voltage Law
D. Watt's Law
Correct Answer: B — Kirchhoff's Current Law
Rationale: Kirchhoff's Current Law (KCL) is based on conservation of charge: current in
equals current out at any node.
10. Which law states the sum of voltage drops in a closed loop equals the source
voltage?
A. Kirchhoff's Current Law
B. Ohm's Law
C. Kirchhoff's Voltage Law
D. Lenz's Law
Correct Answer: C — Kirchhoff's Voltage Law
Rationale: Kirchhoff's Voltage Law (KVL) states the algebraic sum of voltage rises and
drops around a closed loop equals zero.
11. What does a fuse do in a circuit?
A. Increases voltage
B. Protects the circuit from overcurrent by melting/opening
C. Steps down voltage
D. Stores electrical charge
Correct Answer: B — Protects the circuit from overcurrent by melting/opening
Rationale: A fuse contains an element that melts and opens the circuit when current
exceeds its rated value, protecting wiring and components.
, 12. An open circuit has:
A. Zero resistance
B. Infinite resistance
C. Continuous current flow
D. A short circuit condition
Correct Answer: B — Infinite resistance
Rationale: An open circuit has a break in the current path, so resistance measured
across the break is effectively infinite and no current flows.
13. A short circuit is characterized by:
A. Abnormally high resistance
B. Abnormally low resistance, causing excess current
C. No current flow
D. Balanced voltage
Correct Answer: B — Abnormally low resistance, causing excess current
Rationale: A short circuit provides an unintended low-resistance path, causing current
to rise dramatically, often tripping breakers or blowing fuses.
14. The unit of electrical charge is:
A. Ampere
B. Coulomb
C. Farad
D. Henry
Correct Answer: B — Coulomb
Rationale: Electrical charge is measured in coulombs; one ampere equals one
coulomb of charge passing a point per second.
15. One ampere equals:
A. One volt per ohm
B. One coulomb per second
C. One watt per volt
D. One joule per second
Correct Answer: B — One coulomb per second
Rationale: By definition, one ampere is the flow of one coulomb of charge per second.
