#1
What is the unit of resistance?
Ohm (Ω)
ExplanationUnit of electrical resistance.
#2
What is the unit of inductance?
Henry (H)
ExplanationUnit of inductance.
#3
Which of the following materials is commonly used as the core of an inductor?
Iron
ExplanationCommon material for inductor cores due to its magnetic properties.
#4
What is the phenomenon called when the magnetic field collapses around an inductor?
Back electromotive force (EMF)
ExplanationPhenomenon occurring when magnetic field around an inductor collapses.
#5
In a parallel RL circuit, what happens to the total impedance as the number of inductors increases?
It decreases
ExplanationTotal impedance in a parallel RL circuit declines with more inductors.
#6
Which of the following materials exhibits the highest resistance?
Nichrome
ExplanationMaterial commonly used for high-resistance applications.
#7
What is the total resistance of resistors connected in series?
Sum of individual resistances
ExplanationTotal resistance equals the sum of individual resistances.
#8
Which of the following devices stores energy in the form of a magnetic field?
Inductor
ExplanationDevice that stores energy in a magnetic field.
#9
What is the formula for calculating the voltage across an inductor?
V = L * I
ExplanationFormula relating voltage, inductance, and current in an inductor.
#10
Which of the following statements about inductors in DC circuits is true?
Inductors block the flow of DC current
ExplanationInductors prevent the flow of DC current.
#11
Which of the following statements about inductors is correct?
Inductors block DC current but allow AC current to pass through
ExplanationInductors impede DC current but permit AC current flow.
#12
What happens to the inductive reactance of an inductor as frequency increases?
It increases
ExplanationInductive reactance rises with increasing frequency.
#13
What happens to the current through an inductor when the frequency of the applied voltage increases?
Current increases
ExplanationCurrent through an inductor increases with increasing frequency.
#14
In an RL circuit, what happens to the current when the inductor is suddenly connected to a DC source?
The current rises to its maximum value instantaneously
ExplanationCurrent reaches its maximum value immediately upon connection.
#15
What is the time constant of an RL circuit?
The time taken for the current to reach 63.2% of its maximum value
ExplanationTime required for current to reach a specific percentage of its maximum value.
#16
What happens to the magnetic field around an inductor when current flows through it?
The magnetic field expands
ExplanationMagnetic field around an inductor expands with current flow.
#17
In an RL circuit, what is the relationship between the voltage across the resistor and the voltage across the inductor when the circuit is connected to an AC source?
They are 180 degrees out of phase
ExplanationVoltages across resistor and inductor are out of phase in an RL circuit.
#18
What is the relationship between the inductance (L) of an inductor and the number of turns in its coil?
Directly proportional
ExplanationInductance increases proportionally with the number of turns.
#19
What is the phase relationship between the voltage across an inductor and the current flowing through it in an AC circuit?
Voltage leads current by 90 degrees
ExplanationVoltage leads current in an inductor by 90 degrees in an AC circuit.