41. Calculate the active power in an 0 Ω resistor with 0 current flowing through it.
A. inf MW
B. 0 MW
C. 2 MW
D. 18 MW
Answer: B
The resistor is a linear element. It only absorbs real power and dissipates it in the form of heat. The voltage and current are in the same phase in the case of the resistor so the angle between V & I is 0o.
P=I2R=0×0×0=0 MW.
42. When 1 A current flows out of the positive terminal of voltage source 6 V. Calculate the power delivered by the source.
A. 6 W
B. 7 W
C. -9 W
D. -5 W
Answer: A
When the current enters the positive terminal of an element it will always absorb the power and when the current leaves the positive terminal it will deliver the power. Power delivered by the source is
1×6=6 W.
43. Calculate the value of inductor voltage during resonance condition if the value of supply voltage is 7 V and the quality factor is 9.
A. 59 V
B. 63 V
C. 73 V
D. 33 V
Answer: B
During the resonance condition XL=Xc. The value of the inductor voltage is Q×Vs. The power factor of the circuit is one.
Vc=7×9=63 V.
44. A circuit consists of a 3 F capacitor and a 5 H inductor. Determine the order of the circuit.
A. 2
B. 1
C. 3
D. 0
Answer: A
The order of the circuit is the number of memory/storing elements that are non-separable present in the circuit. In mathematics, the order is defined as the highest order derivate in the differential equation. The order of the circuit is 2.
45. The forced response is due to a source present in the circuit.
A. True
B. False
Answer: A
The steady-state response is a part of the forced response. The forced response is due to the electrical source present in the circuit. Its mathematical equation involves the source present in the circuit.
46. Full form of DTC.
A. Direct torque control
B. Digital torque control
C. Discrete torque control
D. Distribution torque control
Answer: A
DTC stands for Direct torque control. DTC and IFOC are the techniques used for controlling the speed and torque of a 3-phase induction motor.
47. The characteristic shown by an element in the I-V curve is V=I2. The nature of the element is _______
A. Non-linear, Bilateral, Passive
B. Linear, Unilateral, Active
C. Linear, Bilateral, Passive
D. Non-linear, Unilateral, Active
Answer: D
The nature of the element is non-linear, unilateral, and active. The shape of the characteristic is parabolic. For bilateral nature, it should be symmetrical in the first and third quadrants. Its slope is negative in the second quadrant which determines its active nature.
48. Transient response is a temporary response.
A. True
B. False
Answer: A
Transient response is a primary response in the circuit. It is a temporary response that dies out at t=infinity. It consists of exponential decaying functions.
49. Calculate the steady-state value for x(t)=4(1-e-3t).
A. 5
B. 4
C. 3
D. 2
Answer: B
The steady-state value is obtained at t=∞.
The value of x(t) at t=∞ is
4(1-e-∞)=4(1-0)=4.
The term e-3t is an exponentially decaying function.
50. The natural response is due to _________ conditions present in the circuit.
A. Initial
B. Final
C. Zero
D. Negative
Answer: A
The natural response is due to the initial conditions present in the circuit. The natural response is a complete part of the transient response. It is mathematically represented as y(t)=yo×e-at.
