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Unit 2 - Practice Quiz

ECE131

1 In the context of AC circuits, which notation is conventionally used to represent the instantaneous value of a voltage?

A.
B.
C.
D.

2 What is the relationship between angular frequency () and linear frequency ()?

A.
B.
C.
D.

3 The time taken by an alternating quantity to complete one full cycle is called:

A. Frequency
B. Amplitude
C. Time Period
D. Phase

4 The maximum value attained by an alternating quantity during a positive or negative half cycle is known as:

A. RMS value
B. Average value
C. Instantaneous value
D. Amplitude

5 For a sinusoidal voltage , what is the Root Mean Square (RMS) value?

A.
B.
C.
D.

6 The average value of a sinusoidal alternating current over one complete cycle is:

A.
B.
C. Zero
D.

7 The average value of a sinusoidal voltage over a half cycle is given by:

A.
B.
C.
D.

8 Which factor is defined as the ratio of RMS value to the Average value?

A. Peak Factor
B. Form Factor
C. Power Factor
D. Q Factor

9 What is the peak factor (crest factor) of a sinusoidal waveform?

A. 1.11
B. 1.414
C. 0.707
D. 0.637

10 Two sinusoidal quantities are said to be in phase quadrature if their phase difference is:

A.
B.
C.
D.

11 In the complex representation of impedance , what does the operator '' represent?

A. Rotation by
B. Rotation by counter-clockwise
C. Rotation by clockwise
D. A scalar multiplier

12 What is the complex impedance of an ideal inductor with inductance at angular frequency ?

A.
B.
C.
D.

13 What is the complex impedance of an ideal capacitor with capacitance ?

A.
B.
C.
D.

14 In a purely resistive AC circuit, what is the phase difference between voltage and current?

A.
B.
C.
D.

15 In a series RL circuit, the current:

A. Leads the applied voltage
B. Lags the applied voltage
C. Is in phase with the voltage
D. Lags the voltage by exactly

16 The magnitude of impedance in a series RL circuit is given by:

A.
B.
C.
D.

17 In a series RC circuit, the phase angle is given by:

A.
B.
C.
D.

18 Which of the following describes the power factor of a series RC circuit?

A. Unity
B. Lagging
C. Leading
D. Zero

19 The total voltage applied to a series RL circuit with resistor voltage and inductor voltage is:

A.
B.
C.
D.

20 For a series RLC circuit, the total impedance is:

A.
B.
C.
D.

21 In a series RLC circuit, if , the circuit behaves as:

A. Resistive
B. Inductive
C. Capacitive
D. Resonant

22 What is the condition for resonance in a series RLC circuit?

A.
B.
C.
D.

23 At resonance, the impedance of a series RLC circuit is:

A. Zero
B. Maximum
C. Minimum and equal to
D. Equal to

24 What is the resonant frequency of a series RLC circuit?

A.
B.
C.
D.

25 At series resonance, the current in the circuit is:

A. Minimum
B. Maximum
C. Zero
D. Infinite

26 The power factor of a series RLC circuit at resonance is:

A.
B. 0.5 lagging
C. 0.5 leading
D. 1 (Unity)

27 The Quality Factor (Q-factor) of a series resonant circuit is given by:

A.
B.
C.
D.

28 In AC circuits, Active Power (Real Power) is calculated as:

A.
B.
C.
D.

29 The unit of Reactive Power () is:

A. Watt (W)
B. Volt-Ampere (VA)
C. Volt-Ampere Reactive (VAR)
D. Joule (J)

30 Apparent Power () is the product of:

A. RMS Voltage and RMS Current
B. Average Voltage and Average Current
C. Peak Voltage and Peak Current
D. Active Power and Power Factor

31 Power factor is defined as the ratio of:

A. Resistance to Impedance ()
B. Impedance to Resistance ()
C. Resistance to Reactance ()
D. Reactance to Resistance ()

32 If the power factor is 0.8 lagging, it means:

A. The circuit is capacitive
B. The circuit is purely resistive
C. Current lags voltage and energy is stored in magnetic fields
D. Current leads voltage

33 In a three-phase system, the voltages of the three phases are displaced from each other by:

A.
B.
C.
D.

34 The order in which the voltages in the three phases reach their maximum positive value is called:

A. Phase Difference
B. Phase Sequence
C. Alternation
D. Frequency

35 In a Star (Wye) connected three-phase system, the relationship between Line Current () and Phase Current () is:

A.
B.
C.
D.

36 In a Star (Wye) connected system, the Line Voltage () relates to the Phase Voltage () as:

A.
B.
C.
D.

37 In a Delta (Mesh) connected three-phase system, the relationship between Line Voltage () and Phase Voltage () is:

A.
B.
C.
D.

38 In a Delta (Mesh) connected system, the Line Current () relates to the Phase Current () as:

A.
B.
C.
D.

39 The total active power in a balanced three-phase circuit (Star or Delta) is given by:

A.
B.
C.
D.

40 Which three-phase connection requires four wires (3 phases + 1 neutral)?

A. Delta Connection
B. Star Connection
C. Mesh Connection
D. Series Connection

41 What is the unit of Admittance ()?

A. Ohm ()
B. Henry (H)
C. Farad (F)
D. Siemens (S) or Mho

42 The real part of Admittance is called:

A. Resistance
B. Reactance
C. Conductance
D. Susceptance

43 If the frequency of the AC supply is increased, the capacitive reactance ():

A. Increases
B. Decreases
C. Remains constant
D. Becomes zero

44 If the frequency of the AC supply is increased, the inductive reactance ():

A. Increases
B. Decreases
C. Remains constant
D. Becomes infinite

45 Which of the following represents the bandwidth of a series RLC circuit?

A.
B.
C.
D. All of the above

46 At half-power frequencies in a series RLC circuit, the current is:

A.
B.
C.
D. Zero

47 The phase angle between Line Voltage and Phase Voltage in a Star connected system is:

A.
B.
C.
D.

48 In a circuit with , what is the magnitude of the impedance?

A.
B.
C.
D.

49 Instantaneous power in a pure resistive circuit is always:

A. Positive
B. Negative
C. Zero
D. Alternating positive and negative

50 What is the value of the 'operator ' squared ()?

A. 1
B. -1
C. j
D.