Introduction to Electrical Engineering MCQs (Part-1)
Which device converts electrical energy into mechanical energy?
A Generator
B Transformer
C Battery
D Motor
An electric motor converts electrical energy into mechanical energy by utilizing electromagnetic principles to produce motion.
What is the SI unit of electric current?
A Ampere
B Ohm
C Volt
D Watt
The SI unit of electric current is the Ampere (A). It measures the flow of electric charge per unit time. One Ampere is defined as one Coulomb of charge passing through a point in one second.
Which law states that the sum of voltages around a closed loop is zero?
A Faraday’s Law
B Kirchhoff’s Voltage Law
C Coulomb’s Law
D Ohm’s Law
Kirchhoff’s Voltage Law (KVL) states that the algebraic sum of all voltages around a closed loop in a circuit is zero, ensuring energy conservation.
What is the unit of electrical resistance?
A Ohm
B Volt
C Ampere
D Joule
The unit of electrical resistance is the Ohm (Ω). It measures the opposition to the flow of electric current in a conductor.
Which of the following is a semiconductor material?
A Silicon
B Copper
C Aluminum
D Silver
Silicon is a semiconductor material widely used in electronic devices due to its ability to conduct electricity under certain conditions and act as an insulator under others.
Which material is the best conductor of electricity?
A Rubber
B Wood
C Glass
D Copper
Copper is an excellent conductor of electricity due to its high free electron density and low resistance. It is widely used in electrical wiring and components.
What is the primary function of a resistor in an electrical circuit?
A Store energy
B Generate voltage
C Control current flow
D Measure power
A resistor is used to limit or control the flow of electric current in a circuit. It provides resistance, which opposes the flow of electrons, thereby regulating current and voltage levels.
Which law states that the current through a conductor is directly proportional to the voltage across it?
A Kirchhoff’s Voltage Law
B Ohm’s Law
C Faraday’s Law
D Coulomb’s Law
Ohm’s Law states that V = I R, where V is voltage, I is current, and R is resistance. It describes the relationship between voltage, current, and resistance in a conductor.
What is the purpose of a fuse in an electrical circuit?
A Increase current flow
B Store energy
C Measure voltage
D Protect against overcurrent
A fuse is a safety device that protects electrical circuits by melting and breaking the circuit when the current exceeds a safe level, preventing damage or fire.
What is the role of an insulator in an electrical system?
A Store electricity
B Block electricity
C Generate electricity
D Conduct electricity
Insulators are materials that resist the flow of electric current. They are used to prevent unwanted current flow and ensure safety in electrical systems.
What does Kirchhoff’s Current Law (KCL) state?
A The sum of voltages in a loop is zero.
B The current in a circuit is proportional to voltage.
C The sum of currents entering a junction equals the sum leaving it.
D The power in a circuit is conserved.
Kirchhoff’s Current Law (KCL) states that the total current entering a junction in a circuit must equal the total current leaving it, ensuring charge conservation.
Which of the following is a passive electrical component?
A Diode
B Resistor
C Transistor
D Battery
A resistor is a passive component because it does not generate energy. It only consumes or dissipates energy in the form of heat.
Which of the following is a renewable energy source?
A Coal
B Nuclear power
C Solar power
D Natural gas
Solar power is a renewable energy source that harnesses energy from the sun using photovoltaic cells or solar panels, making it sustainable and environmentally friendly.
What is the formula for electrical power?
A P = I R
B P = V / R
C P = V I
D P = V / R
Electrical power is calculated using the formula P = V I, where P is power in watts, V is voltage in volts, and I is current in amperes.
What is the direction of conventional current flow in a circuit?
A Positive to negative
B Negative to positive
C Random direction
D No specific direction
Conventional current flow is defined as the flow of positive charge from the positive terminal to the negative terminal of a power source.