Introduction to Electrical Engineering MCQs (Part-6)
What is the main difference between AC and DC?
A Current direction
B Circuit type
C Voltage level
D Power consumption
Alternating Current (AC) reverses its direction periodically, while Direct Current (DC) flows in one constant direction. AC is used in power distribution, while DC is used in electronic devices and batteries.
What is the function of a rectifier?
A Control current flow
B Store energy
C Convert AC to DC
D Convert DC to AC
A rectifier converts alternating current (AC) to direct current (DC). It allows current to flow in only one direction, making it essential in power supplies that provide DC for devices like computers and chargers.
What does the symbol “V” represent in electrical circuits?
A Resistance
B Voltage
C Power
D Current
“V” represents voltage in electrical circuits, which is the electrical potential difference between two points. It drives the current through the circuit and is a key factor in determining energy consumption.
Which component is used to measure electrical resistance?
A Wattmeter
B Ammeter
C Voltmeter
D Ohmmeter
An ohmmeter is used to measure the electrical resistance in a circuit. It works by applying a known current and measuring the resulting voltage to calculate the resistance using Ohm’s Law.
What is the purpose of a fuse in an electrical circuit?
A To measure voltage
B To store energy
C To prevent overload
D To increase current
A fuse protects the circuit by breaking the connection if the current exceeds a safe level. It prevents overheating and potential damage to components by limiting the flow of excess current.
In a series circuit, how is the total resistance calculated?
A Add the resistances
B Multiply the resistances
C Divide the resistances
D Add the reciprocals
In a series circuit, the total resistance is the sum of all individual resistances. As more resistors are added, the total resistance increases, limiting the amount of current that flows through the circuit.
What is the unit of electrical power?
A Ohm
B Volt
C Watt
D Ampere
The unit of electrical power is the Watt (W). It is the rate at which electrical energy is converted or used in a circuit. Power can be calculated using P=V×I, where V is voltage and I is current.
What does a capacitor do in an electrical circuit?
A Increase current
B Store charge
C Limit resistance
D Measure voltage
A capacitor stores electrical energy in an electric field created between two conductive plates. It can release the stored energy when needed, making it useful for smoothing voltage fluctuations and filtering signals.
What happens to current in a parallel circuit if one branch is disconnected?
A Current stops
B Current decreases
C Current increases
D Current stays the same
In a parallel circuit, if one branch is disconnected, the current in the remaining branches remains the same. This is because the total resistance in the circuit decreases, and current will flow through the other paths.
What does a potentiometer control in a circuit?
A Power
B Voltage
C Resistance
D Current
A potentiometer is a variable resistor that allows the user to adjust the resistance in a circuit. By changing the resistance, it controls the current and voltage, commonly used for adjusting things like volume or light intensity.
What is the unit of electric current?
A Ampere
B Watt
C Volt
D Ohm
The unit of electric current is the Ampere (A). It is defined as the amount of charge flowing through a conductor per second. One ampere is equivalent to one coulomb of charge passing a point per second.
Which component blocks the flow of current in one direction?
A Inductor
B Diode
C Resistor
D Capacitor
A diode is a semiconductor component that allows current to flow in only one direction. It blocks the reverse current, making it useful in converting AC to DC and protecting circuits from damage.
What does Kirchhoff’s Voltage Law state?
A Power is conserved
B Total voltage is constant
C Total voltage in a loop is zero
D Current is conserved
Kirchhoff’s Voltage Law (KVL) states that the sum of all voltages around any closed loop in a circuit must be zero. This law helps analyze circuits by ensuring that energy is conserved in the system.
What does an ammeter measure in an electrical circuit?
A Voltage
B Resistance
C Power
D Current
An ammeter is used to measure the electric current flowing through a circuit. It is connected in series with the load, and it helps determine if the current is within safe operating limits.
What type of current does a battery provide?
A Direct Current
B Alternating Current
C Pulsating Current
D High Frequency Current
A battery provides Direct Current (DC), which flows in one consistent direction. DC is commonly used in devices like flashlights, mobile phones, and laptops, where a steady voltage is required.