Free IEM Electrical Systems & Circuit Analysis Questions and Answers — Questions and Answers
Question 1: What does Ohm's Law relate in an electrical circuit?
- Voltage, resistance, and capacitance
- Current, inductance, and voltage
- Voltage, current, and resistance (Correct answer)
- Resistance, power, and frequency
Correct answer: Voltage, current, and resistance
Ohm's Law is a fundamental principle in electrical engineering that describes the relationship between voltage (V), current (I), and resistance (R) in an electrical circuit. It is mathematically expressed as V = I * R, meaning voltage is directly proportional to current and resistance.
Question 2: In a series circuit, how does the total resistance compare to individual resistances?
- It is the same as the smallest resistance.
- It is the average of all resistances.
- It is the sum of all resistances. (Correct answer)
- It is less than the smallest resistance.
Correct answer: It is the sum of all resistances.
In a series circuit, components are connected end-to-end, forming a single path for current flow. The total resistance of the circuit is found by simply adding up the individual resistances of each component, as each resistor contributes to the overall opposition to current.
Question 3: What is the main function of a capacitor in an AC circuit?
- To resist current flow
- To store electrical charge (Correct answer)
- To produce electromagnetic waves
- To amplify the voltage
Correct answer: To store electrical charge
A capacitor is an electronic component designed to store electrical energy in an electric field. In an AC circuit, capacitors repeatedly charge and discharge, allowing them to block DC current while passing AC current, and are used for filtering, timing, and energy storage.
Question 4: Which device is used to measure current in a circuit?
- Voltmeter
- Ammeter (Correct answer)
- Ohmmeter
- Oscilloscope
Correct answer: Ammeter
An ammeter is a specialized measuring instrument used to determine the electric current flowing through a point in a circuit. It is always connected in series with the circuit component through which the current is to be measured, to ensure all the current passes through it.
Question 5: What happens to total current in a parallel circuit when more branches are added?
- It decreases.
- It stays the same.
- It increases. (Correct answer)
- It drops to zero.
Correct answer: It increases.
In a parallel circuit, adding more branches provides additional paths for current to flow. Each new branch effectively reduces the overall equivalent resistance of the circuit, which, according to Ohm's Law (I=V/R), results in an increase in the total current drawn from the power source.
Free IEM Electrical Systems & Circuit Analysis Questions and Answers
What does Ohm's Law relate in an electrical circuit?