Test: Different of Circuit - Electrical Engineering (EE) MCQ

The instantaneous voltage is a product of the instantaneous current and the resistance in the circuit.

We know that,
v=iR, substituting the given values from the question, we get v=10V.

The power in a resistive circuit is the product of the voltage, current and the cosine of the phase angle. Hence if either voltage or current is zero, the power is zero.

We know that:
Im=Vm/R
Substituting the given values from the question, we get Im=2A.

We know that:
R=V/I
Substituting the given values from the question, we get R=10 ohm.

P=VIcosϕ Power in a circuit is the product of voltage, current and the cosine of the phase angle. Phase angle is 00 for purely resistive circuit so, P=VI. Hence if either voltage or current is zero, the power is zero.

 Ohm’s law can be applied in ac as well as dc circuits. It can be applied in ac circuits because the condition V=IR holds true even in ac circuits.

The average value of current is the sum of all the currents divided by the number of currents.

Effective current is also known as the effective current. RMS stands for Root Mean Square. This value of current is obtained by squaring all the current values, finding the average and then finding the square root.

The average value of current is the sum of all the currents divided by the number of currents. Therefore average current= (5+4+6)/3=5A.

The formula for frequency in an inductive circuit is:
XL=2*pi*f*L.
Therefore: L is inversly proportional to f.

The power factor is the cosine of the angle in between the voltage and the current. If the angle between the voltage and current is 90, then cos90=0. Hence, the power factor is zero.

We know that:
cos(ϕ) = R/Z
R = Z cos(ϕ) = 20/10 = 2 ohm.

Inductive reactance is nothing but the impedance. Impedance is the AC equivalent of resistance, hence the unit for inductive reactance is ohm.

The average current is the average of the current which flows in the inductor. Hence it is I/2.

Bulbs are connected in parallel so that even if one of the bulbs blow out, the others continue to get a current supply.

The expression for emf in an inductive circuit is:
emf= LI/t
Substituting the values from the given question, we get emf= 5V.

The expression for energy in an inductor is:
W= LI²/2
Substituting the values from the given question, we get I=4A.

The expression for power in an inductive circuit is:
P= LI²/2
Substituting the values from the given question, we get t=4s.

Any circuit in which a change of current is accompanied by a change of flux, and therefore by an induced emf, is said to be inductive.

Current=rate of change of charge=> I=dQ/dt. Q=CV, hence I=CdQ/dt.

 Q is directly proportional to V. The constant of proportionality in this case is C, that is, the capacitance. Hence Q=CV.
Q=3*2=6C.
I=Q/t= 6/2=3A.

Q is directly proportional to V. The constant of proportionality in this case is C, that is, the capacitance. Hence Q=CV.
Q=3*2=6C.

Q is directly proportional to V. The constant of proportionality in this case is C, that is, the capacitance. Hence Q=CV.

When a capacitor is fully charged, it does not store any more charge. There is no change in charge with time. Current is the rate of change of charge, hence it becomes zero, or stops.

Capacitive impedance is inversely proportional to frequency. Hence at very high frequencies, the impedance is almost equal to zero, hence it acts as a short circuit and there is no voltage across it.

Capacitive impedance is inversely proportional to frequency. Hence at very low frequencies the impedance is almost infinity and hence acts as an open circuit and no current flows through it.

Mica capacitors are preferred for high frequency circuits because they have low ohmic losses and less reactance.

Q is directly proportional to V. The constant of proportionality in this case is C, that is, the capacitance.

Hence Q = CV.

V = Q/C = 1/2

V = 0.5V.

At the time of switching, when t=0, the capacitor acts as a short circuit. The voltage across a short is always equal to zero hence the voltage across the capacitor is equal to zero.