Introduction to Electrical Engineering MCQs (Part-12)
What is the function of a multimeter?
A Measure resistance
B Measure voltage
C Measure current
D All of the above
A multimeter is a versatile tool that can measure voltage, current, and resistance. It is commonly used in circuit analysis and troubleshooting to check the electrical characteristics of components and circuits.
What does a power supply provide to a circuit?
A Voltage
B Energy
C Resistance
D Current
A power supply provides voltage to a circuit. It is responsible for maintaining a constant voltage level and converting electrical energy to a form that can be used by the components in the circuit.
Which of these devices is used to limit the flow of current?
A Inductor
B Resistor
C Diode
D Capacitor
A resistor is used to limit or control the flow of current in a circuit. It resists the flow of electrons, thus reducing the current to safe levels for the other components in the circuit.
What type of device is a fuse?
A Power converter
B Signal amplifier
C Current protection device
D Voltage regulator
A fuse is a safety device used to protect a circuit from excessive current. It contains a wire that melts when the current exceeds a certain level, breaking the circuit and preventing damage to components.
What is the primary function of a diode in a circuit?
A Increase current
B Control current direction
C Store energy
D Measure current
A diode allows current to flow in only one direction, effectively controlling the direction of current in a circuit. It is widely used in rectifiers to convert AC to DC and protect circuits from reverse current.
Which instrument is used to measure resistance?
A Wattmeter
B Ammeter
C Ohmmeter
D Voltmeter
An ohmmeter is specifically used to measure the resistance of a component or circuit. It applies a small current and measures the resulting voltage to calculate the resistance in ohms (Ω).
What does a capacitor store in a circuit?
A Energy
B Power
C Voltage
D Current
A capacitor stores electrical energy in the form of an electric field. It can release this energy when needed, which is essential for smoothing power supplies, filtering signals, and providing quick bursts of energy in circuits.
What is the primary purpose of a transformer in an electrical system?
A Step-down voltage
B Change voltage level
C Convert AC to DC
D Step-up voltage
An electrical transformer is used to change the voltage level of alternating current (AC). It can step up (increase) or step down (decrease) the voltage, depending on the number of coils in the primary and secondary windings.
Which of the following is an example of an active component in a circuit?
A Diode
B Capacitor
C Transistor
D Resistor
A transistor is an active component in a circuit because it can amplify electrical signals or act as a switch. It requires an external power source to operate, unlike passive components such as resistors and capacitors.
What is the purpose of a voltmeter in a circuit?
A Measure power
B Measure voltage
C Measure current
D Measure resistance
A voltmeter is used to measure the potential difference, or voltage, between two points in a circuit. It is connected in parallel with the component or section of the circuit where the voltage is to be measured.
What happens when two resistors are connected in parallel?
A The total resistance decreases
B Current is halved
C The total resistance stays the same
D The total resistance increases
When resistors are connected in parallel, the total resistance decreases. The reciprocal of the total resistance is the sum of the reciprocals of the individual resistances. Adding more parallel resistors provides more paths for current flow.
What is the role of an inductor in a circuit?
A Control current flow
B Convert AC to DC
C Store magnetic energy
D Store electrical energy
An inductor stores energy in a magnetic field when current flows through it. It resists changes in current, making it useful for filtering applications and energy storage in circuits where current regulation is required.
Which of the following is a key characteristic of an insulator?
A Controls current direction
B Resists the flow of current
C Allows current to flow
D Stores electrical energy
An insulator is a material that resists the flow of electrical current. It is used to coat wires and prevent accidental contact with live circuits, ensuring safety in electrical systems.
What happens to current in a series circuit when one component is removed?
A Current increases
B Current stays the same
C Current stops
D Current doubles
In a series circuit, if one component is removed, the entire circuit is broken, and current stops flowing. This is because current in a series circuit flows through each component sequentially, and any break disrupts the current.
What type of current does a battery produce?
A Pulsating Current
B Alternating Current (AC)
C High Frequency Current
D Direct Current (DC)
A battery produces Direct Current (DC), where the electric charge flows in one direction. DC is used in devices like batteries, electronics, and solar panels, which require a steady flow of current.