In a DC circuit, a capacitor stores energy in the form of an electric field. It charges up when connected to a DC source and blocks DC current after being fully charged, acting as an open circuit.
What happens at the cutoff frequency in an RLC circuit?
A Power is constant
B Current is maximum
C Impedance is maximum
D Voltage is minimum
At the cutoff frequency in an RLC circuit, the impedance is maximum, causing the circuit to behave as if it has a high resistance. This marks the point where the circuit transitions from pass-band to stop-band.
In a parallel circuit, the total resistance is?
A Always less
B Zero
C Always greater
D Equal to resistance
In a parallel circuit, the total resistance is always less than the smallest individual resistance. The total resistance is found by taking the reciprocal of the sum of reciprocals of individual resistances.
What does Laplace Transform help in circuit analysis?
A Solves for time
B Measures power
C Simplifies AC
D Converts circuits to frequency domain
The Laplace Transform is used in circuit analysis to convert time–domain functions into the frequency domain. This helps solve differential equations in circuits and analyze system behavior easily.
Which of the following is used for current division in parallel circuits?
A Current ratio
B Power formula
C Ohm’s Law
D Voltage divider
In a parallel circuit, current division is determined by applying Ohm’s Law, where the current divides inversely proportional to the resistances of the branches. The larger the resistance, the smaller the current.
What is true about the transient response of a circuit?
A Initial change in voltage
B Change after a long time
C Behavior after shock
D Steady-state behavior
The transient response of a circuit refers to the initial changes in voltage and current when a switch is turned on or off. This phase occurs before the circuit settles into its steady–state condition.
Which of the following components stores energy in a magnetic field?
A Resistor
B Diode
C Capacitor
D Inductor
An inductor stores energy in the form of a magnetic field when current flows through it. It resists changes in current and releases the stored energy when the current is altered.
What does Norton’s Theorem simplify?
A Voltage sources
B Complex circuits
C Parallel resistances
D Impedance
Norton’s Theorem simplifies a complex linear circuit into an equivalent current source in parallel with a resistance. This makes it easier to analyze and solve for currents or voltages in the circuit.
Thevenin’s equivalent resistance is found by?
A Short–circuiting all sources
B Using mesh analysis
C Applying Kirchhoff’s laws
D Measuring voltage
To find Thevenin’s equivalent resistance, all independent voltage and current sources are replaced with their internal resistances (voltage sources are short–circuited and current sources are open–circuited).
What does the power factor indicate in AC circuits?
A Phase difference
B Voltage regulation
C Efficiency of energy usage
D Total power consumed
The power factor in AC circuits represents the efficiency with which electrical power is being used. A power factor of 1 indicates perfect efficiency, meaning all power is used effectively.
What is the purpose of a voltage divider circuit?
A Increase power
B Maximize resistance
C Divide voltage
D Reduce current
A voltage divider circuit splits the input voltage into smaller, proportionate voltages across the resistors. It is commonly used to obtain specific voltage levels from a higher voltage source.
What is reactance?
A Resistance to AC
B Phase shift
C Flow of charge
D Power loss
Reactance is the opposition to the flow of alternating current, caused by capacitors and inductors in AC circuits. It varies with the frequency of the signal and is measured in ohms.
What is the main characteristic of resonance in RLC circuits?
A Power is minimized
B Current is maximum
C Impedance is high
D Voltage is zero
At resonance in an RLC circuit, the inductive reactance and capacitive reactance cancel each other out, resulting in the lowest impedance and maximum current flowing through the circuit.
What is the effect of inductive reactance on current?
A Causes phase shift
B No effect
C Decreases current
D Increases current
Inductive reactance opposes the change in current in an AC circuit. As the frequency of the AC increases, inductive reactance increases, which decreases the current flowing through the circuit.
Which of the following is a steady-state response characteristic?
A Changing voltage
B Initial energy storage
C Time–varying current
D Constant current
The steady–state response is the behavior of a circuit once it has settled after transient conditions. It involves constant current and voltage, where no further changes occur in the circuit’s operation.