Electrical Circuits Exam 2026/2027

Ohm's Law to MOSFETs | 110 Multiple-
Choice Questions & Answers | Electrical
Engineering Exam 2026/2027

Description:
Master circuit analysis, transistors, op-amps, digital logic, and AC theory. 110 exam-style
questions with full explanations. Updated for 2026/2027 academic standards.



Download the complete practice exam now.

, Electrical Circuits Exam 2026/2027
Academic Year: 2026/2027
Examination Type: Midterm Examination
Time Allowed: 90 Minutes

Instructions: Select the best answer for each multiple-choice question. Each question has
one correct answer unless otherwise stated.

Section A: Ohm’s Law & Basic Circuit Analysis

1. Which of the following correctly represents Ohm’s Law?

 A. R = I × V

 B. V = I / R

 C. I = V × R

 D. V = I × R

Answer: D
Explanation: Ohm’s Law states that the voltage (V) across a resistor is equal to the product
of the current (I) flowing through it and its resistance (R). The alternative forms are I = V/R
and R = V/I.

2. In a DC circuit where the voltage remains constant, if the current decreases, what must
happen to the resistance?

 A. Resistance must decrease

 B. Resistance must remain the same

 C. Resistance must increase

 D. Resistance becomes zero

Answer: C
Explanation: According to Ohm’s Law (R = V/I), resistance and current are inversely
proportional when voltage is constant. Therefore, a decrease in current requires an increase in
resistance.

,3. A circuit has a constant voltage supply of 24 V. If the total resistance is reduced from 12 Ω
to 6 Ω, the current will:

 A. Decrease from 2 A to 1 A

 B. Increase from 2 A to 4 A

 C. Remain at 2 A

 D. Increase from 4 A to 8 A

Answer: B
Explanation: Using I = V/R, initially I = 24 V / 12 Ω = 2 A. After reduction, I = 24 V / 6 Ω =
4 A. Thus, current doubles when resistance is halved.

4. What is the most direct cause of a decrease in current, assuming the voltage source remains
unchanged?

 A. A decrease in resistance

 B. An increase in resistance

 C. A decrease in power

 D. An increase in capacitance

Answer: B
Explanation: For a constant voltage, current and resistance are inversely related. Increasing
resistance reduces current flow, as described by I = V/R.

Section B: Circuit Faults & Protection Devices

5. What is the technical definition of a short circuit?

 A. An open path with infinite resistance

 B. A zero-resistance path causing excessively high current

 C. A high-resistance path causing voltage drop

 D. A path with resistance equal to the load

Answer: B
Explanation: A short circuit is an unintended low-resistance (near zero) connection between
two points in a circuit, which allows a dangerously high current to flow.

, 6. An electronic shunt used for circuit protection is commonly known as a:

 A. Rectifier

 B. Crowbar circuit

 C. Voltage divider

 D. Transformer

Answer: B
Explanation: A crowbar circuit is a type of shunt protection that rapidly creates a short
circuit across the power supply when an overvoltage condition is detected, blowing a fuse or
tripping a breaker.

7. How does a shunt-based crowbar protection circuit operate during an overvoltage event?

 A. It opens the circuit to stop all current

 B. It creates a short circuit, causing a voltage drop and high current that opens a fuse

 C. It increases resistance to limit current

 D. It stores excess voltage in a capacitor

Answer: B
Explanation: Upon detecting overvoltage, the crowbar circuit shorts the supply, causing the
voltage to collapse and a large current to flow. This high current activates a current-sensitive
device like a fuse or circuit breaker.

Section C: Power & Energy Transmission

8. Which formula correctly states the electrical power relationship?

 A. P = R × I

 B. P = V / I

 C. P = V × I

 D. P = V + I

Answer: C
Explanation: The basic power formula is P = V × I (watts = volts × amperes). This can be
combined with Ohm’s Law to derive P = I²R or P = V²/R.