What does **power factor correction** help improve in an electrical circuit?
A The voltage drop across components
B The efficiency of power usage by reducing losses
C The amount of energy stored in the circuit
D The current flow through the circuit
Power factor correction aims to align the current and voltage waveforms in phase, reducing the reactive power and ensuring that more electrical energy is used effectively for work, improving the overall efficiency.
Which of the following is an example of a **passive component**?
A Resistor
B Diode
C Transistor
D Operational amplifier
Passive components do not supply power to the circuit but rather either store energy or dissipate it. A resistor is a passive component because it dissipates energy as heat without amplifying or generating energy.
Which component is considered an **active component** in an electrical circuit?
A Capacitor
B Resistor
C Transistor
D Inductor
Active components are capable of controlling or amplifying electrical signals. A **transistor** is an active component that can amplify or switch signals in circuits.
What does **feedback** in an electrical circuit typically do?
A Increase the voltage across a component
B Stabilize and control the output of the circuit
C Decrease the current through the circuit
D Reduce the power consumed
Feedback in electrical circuits, especially amplifiers, is used to control and stabilize the output. Negative feedback is often used to reduce gain fluctuations and improve the system’s performance.
What is the main function of **electrical filters** in circuits?
A To convert AC to DC
B To increase the current
C To pass certain frequencies while blocking others
D To amplify signals
**Electrical filters** allow certain frequencies to pass through while blocking others. They are essential in signal processing, communication systems, and audio systems to clean up unwanted noise.
What is an **equivalent circuit** used for in electrical analysis?
A To represent a circuit with only resistors
B To simplify a complex circuit for easier analysis
C To add more components to a circuit
D To increase the total resistance of a circuit
An **equivalent circuit** is a simplified version of a complex circuit that replaces components with simpler models, making it easier to analyze and solve.
What is **energy transfer** in an electrical circuit?
A The conversion of electrical energy into heat
B The process of transferring energy from the source to the load
C The storage of energy in resistive components
D The dissipation of power as heat
**Energy transfer** refers to the process by which electrical energy flows from the **source** to the **load**, where it is consumed, stored, or converted into another form of energy.
What is the primary function of **digital circuits**?
A To process signals in continuous values
B To process signals in discrete values (0 and 1)
C To store energy
D To control the current in a circuit
**Digital circuits** process signals in discrete values, typically binary (0 and 1). They are used in systems like computers, logic gates, and other digital technologies.
In **circuit design**, what is a common technique to simplify complex circuits?
A Using more complex components
B Using equivalent circuits to represent parts of the system
C Avoiding the use of passive components
D Using more active components
**Circuit simplification** involves using **equivalent circuits** to reduce the complexity of a system, making it easier to analyze and design.
What happens to the **current** in a **series circuit** when the resistance increases?
A The current increases
B The current decreases
C The current remains the same
D The current becomes zero
According to **Ohm’s Law** (**V = I * R**), increasing the total resistance in a **series circuit** causes the current to decrease, assuming the voltage remains constant.
What is the **cutoff frequency** in an electrical filter?
A The frequency at which the impedance is zero
B The frequency at which the filter begins to pass the signal
C The maximum frequency the filter can pass
D The frequency at which power is minimized
The **cutoff frequency** is the point at which a filter starts to pass the signal with minimal attenuation. Above or below this frequency, the filter reduces the signal strength.
What does **power factor correction** aim to reduce in an AC circuit?
A The resistance of the load
B The phase difference between current and voltage
C The voltage drop across the circuit
D The total power consumption
**Power factor correction** reduces the phase difference between the voltage and current waveforms, improving the efficiency of the circuit by minimizing reactive power.
What is the role of **capacitors** in an electrical circuit?
A To store energy in an electric field
B To increase the current in the circuit
C To resist changes in current
D To store energy in a magnetic field
**Capacitors** store electrical energy in the form of an **electric field** between their plates. They can release this energy when required in AC circuits, making them useful for filtering and smoothing applications.
In an AC circuit, what happens to the **impedance** of a capacitor as the frequency increases?
A It increases
B It decreases
C It remains the same
D It becomes zero
In an AC circuit, the **capacitive reactance (XC)** decreases as the frequency increases. The formula is **XC = 1 / (2πfC)**, where **f** is the frequency and **C** is the capacitance.
What is the **resonance** frequency in an RLC circuit determined by?
A The voltage of the circuit
B The values of resistance, inductance, and capacitance
C The total current in the circuit
D The phase angle between current and voltage
The **resonance frequency** in an RLC circuit is determined by the values of **resistance (R)**, **inductance (L)**, and **capacitance (C)**, specifically by the formula:
**f_resonance = 1 / (2π√(LC))**.
What is the **phase shift** between current and voltage in a purely resistive AC circuit?
A 0 degrees
B 45 degrees
C 90 degrees
D 180 degrees
In a **purely resistive** AC circuit, the voltage and current are **in phase**, meaning they peak and zero out at the same time, resulting in a **0-degree phase shift**.
What is the **energy transfer** in an electrical circuit?
A The conversion of electrical energy into heat
B The process of transferring energy from the source to the load
C The storage of energy in resistive components
D The dissipation of power as heat
**Energy transfer** refers to the process of moving energy from the **source** (like a battery or power supply) to the **load** (such as a lightbulb or motor), where it is consumed, stored, or converted into another form of energy.
What is the primary function of **digital circuits**?
A To process signals in continuous values
B To process signals in discrete values (0 and 1)
C To store energy
D To control the current in a circuit
**Digital circuits** process signals in discrete values, typically binary (0 and 1). They are used in systems like computers, logic gates, and other digital technologies.
In **circuit design**, what is a common technique to simplify complex circuits?
A Using more complex components
B Using equivalent circuits to represent parts of the system
C Avoiding the use of passive components
D Using more active components
**Circuit simplification** involves using **equivalent circuits** to reduce the complexity of a system, making it easier to analyze and design.
What happens to the **current** in a **series circuit** when the resistance increases?
A The current increases
B The current decreases
C The current remains the same
D The current becomes zero
According to **Ohm’s Law** (**V = I * R**), increasing the total resistance in a **series circuit** causes the current to decrease, assuming the voltage remains constant.