Introduction to Electrical Engineering MCQs (Part-4)
What is the unit of electrical power?
A Watt
B Ampere
C Ohm
D Volt
The unit of electrical power is the Watt (W). It measures the rate at which electrical energy is used or produced in a circuit. Power is calculated using the formula P = V × I, where power, voltage, and current are interrelated.
What is the effect of increasing resistance in a circuit?
A Increases power
B No effect
C Decreases current
D Increases current
According to Ohm’s Law, increasing resistance in a circuit decreases the current, assuming voltage remains constant. The current is inversely proportional to resistance, which means higher resistance leads to less current flow.
What type of current is commonly used in homes?
A Static Current
B Alternating Current
C Direct Current
D High Frequency Current
Alternating Current (AC) is commonly used in homes for electrical power distribution. It alternates direction periodically, making it easier to generate and transmit over long distances, unlike Direct Current (DC).
What is the function of a fuse in a circuit?
A To measure current
B To increase current
C To control voltage
D To protect from overload
A fuse is a protective device that prevents circuit overload. It contains a wire that melts if the current exceeds a safe level, interrupting the circuit and preventing damage to electrical components or fires.
What does the electric potential of a charge depend on?
A Current
B Voltage
C Distance
D Resistance
Electric potential energy depends on the distance between charges. The farther a charge is from another, the higher the potential energy. It also depends on the magnitude of the charge and the configuration of the electric field.
What does the symbol “Ω” represent in a circuit?
A Resistance
B Power
C Voltage
D Current
The symbol “Ω” represents Ohms, the unit of electrical resistance. Resistance is a property that opposes the flow of electric current in a conductor, and it is calculated using Ohm’s Law.
Which of the following components stores energy in a magnetic field?
A Transistor
B Capacitor
C Inductor
D Resistor
An inductor stores energy in a magnetic field when current flows through it. It resists changes in the current and is commonly used in circuits for filtering or energy storage applications.
What is the purpose of a circuit diagram?
A To calculate resistance
B To represent a circuit’s layout
C To show voltage levels
D To show current
A circuit diagram is a graphical representation of an electrical circuit. It shows the components and their connections, allowing for easier understanding, analysis, and troubleshooting of the circuit.
What does a capacitor do in a DC circuit?
A Stores energy
B Controls current
C Reduces resistance
D Increases voltage
In a DC circuit, a capacitor stores electrical energy in the form of an electric field. It charges up when current flows and discharges when the circuit demands energy, used in smoothing voltage fluctuations.
What does the term “electrical load” refer to?
A The current flowing through a circuit
B The voltage across a circuit
C The resistance of a circuit
D The devices using electrical energy
The electrical load refers to the devices or components in a circuit that consume electrical energy. These can be appliances, lights, motors, etc., and they determine the amount of current needed in a circuit.
What is the relationship between current and voltage in an ohmic conductor?
A Directly proportional
B Inversely proportional
C Directly proportional to power
D Unrelated
In an ohmic conductor, current and voltage are directly proportional, according to Ohm’s Law. This means that as voltage increases, current increases, provided resistance remains constant.
What is the purpose of an electrical circuit’s ground?
A To store electrical energy
B To increase current
C To reduce voltage
D To provide a safe path for current
The ground in an electrical circuit provides a safe path for current to flow in case of a fault or short circuit. It prevents electrical shocks by directing excess current away from electrical devices and people.
What does a voltage source do in a circuit?
A Reduces voltage
B Provides resistance
C Supplies electrical energy
D Increases current
A voltage source, such as a battery or power supply, provides electrical energy to a circuit by creating a potential difference (voltage) that drives the flow of current through the circuit.
Which component is used to vary the resistance in a circuit?
A Diode
B Potentiometer
C Resistor
D Capacitor
A potentiometer is a type of variable resistor that allows you to adjust the resistance in a circuit. It is commonly used to control the level of voltage or current, such as in volume controls or light dimmers.
What does a multimeter measure?
A Voltage
B Resistance
C Current
D All of the above
A multimeter is a versatile tool used to measure resistance, current, and voltage in an electrical circuit. It can be used to troubleshoot and diagnose issues by providing various electrical measurements.