Kirchhoff’s Voltage Law (KVL) states that the sum of all the voltages around a closed loop in a circuit is zero. This is because the total energy gained by charges is equal to the energy lost.
What is the primary use of mesh analysis?
A Find current
B Calculate power
C Find voltage
D Find impedance
Mesh analysis is primarily used to find the currents in each mesh (loop) of a circuit by applying Kirchhoff’s Voltage Law (KVL) to the loops. It simplifies complex circuits by focusing on current distribution.
What is the effect of increasing resistance in a series circuit?
A Increases voltage
B Increases current
C No effect
D Decreases current
In a series circuit, the total resistance increases as you add resistors. According to Ohm’s Law (V = IR), if resistance increases, the current decreases, assuming constant voltage across the circuit.
What is the role of a ground in a circuit?
A Stabilize power
B Provide reference voltage
C Increase current flow
D Reduce resistance
A ground in a circuit serves as a common reference point for measuring voltages. It provides a stable point of zero potential and ensures that the voltage levels in the circuit are correctly referenced.
Which of the following is used to simplify complex networks?
A Thevenin’s theorem
B Voltage division
C Mesh analysis
D Impedance matching
Thevenin’s theorem simplifies complex linear circuits into a simple equivalent circuit with a single voltage source and series resistance. This makes analysis easier, especially when finding current or voltage across a load.
What happens in a parallel RLC circuit at resonance?
A Voltage is constant
B Maximum current
C Minimum impedance
D Maximum voltage
At resonance in a parallel RLC circuit, the inductive and capacitive reactances cancel each other out, resulting in minimum impedance. This condition allows maximum current to flow through the circuit.
What is the function of an inductor in a circuit?
A Increase current
B Store magnetic energy
C Convert DC to AC
D Store electrical energy
An inductor stores energy in a magnetic field when current flows through it. It resists changes in current and releases energy when the current changes, making it useful for filtering and energy storage.
In an AC circuit, what happens when the phase angle is zero?
A Power is halved
B Maximum impedance
C No power loss
D Voltage and current are in phase
When the phase angle is zero, the voltage and current in an AC circuit are in phase with each other. This results in maximum power transfer with no reactive power, making the system efficient.
Which of the following is an example of a reactive component?
A Switch
B Battery
C Capacitor
D Resistor
A capacitor is a reactive component because it stores energy in an electric field. It resists changes in voltage in AC circuits, causing phase shifts and affecting impedance, unlike resistors which only dissipate energy.
What is the main principle behind the Superposition Theorem?
A Consider one source at a time
B Simplify voltage
C Maximize power
D Find impedance
The Superposition Theorem states that in a linear circuit with multiple independent sources, the current or voltage in any branch can be calculated by considering each source separately and then summing the results.
In a resonance circuit, which quantity is minimized?
A Power
B Voltage
C Current
D Impedance
In a resonance circuit, whether series or parallel, the impedance is minimized (for parallel circuits) or maximized (for series circuits). This allows maximum energy transfer and efficiency at the resonant frequency.
What does a phasor diagram represent?
A Total power
B Voltage polarity
C Relationship between voltages and currents
D Current flow
A phasor diagram visually represents the relationship between voltages and currents in an AC circuit. It shows the magnitude and phase angle of voltages and currents as vectors, helping analyze phase differences.
What is the transient response of a circuit?
A Constant voltage level
B Instantaneous response to changes
C Long-term behavior
D Power distribution
The transient response refers to the temporary behavior of a circuit immediately after a sudden change, such as when a switch is closed. This phase eventually settles into the steady–state response of the circuit.
What is the characteristic of an ideal voltage source?
A Constant current
B Infinite power
C Zero resistance
D Variable voltage
An ideal voltage source is one that can maintain a constant voltage regardless of the current drawn by the circuit. It has zero internal resistance and can provide unlimited current as needed, which is idealized in theory.
Which of the following statements is true about AC circuits?
A Current and voltage alternate
B Voltage is constant
C Energy is not transferred
D Power remains constant
In AC circuits, the voltage and current alternate directions periodically, following a sinusoidal waveform. This alternating current changes direction, unlike direct current (DC), which flows in a single direction.