Networks Analysis and Synthesis

Question: In a series L-C circuit fed by ac voltage, voltage drops across L and C are 40 V and 30 V respectively. The supply voltage is
[A].

70 V

[B].

10 V

[C].

50 V

[D].

1.333 V

Answer: Option C

Explanation:

|V| = IXL – IXC.

Question: A current 10 sin (200t) A flows through a 5 mH inductance. The expression for voltage is
[A].

10 sin (200t + 90°)

[B].

10 sin (200t – 90°)

[C].

10 sin(1000t + 90°)

[D].

10 sin (1000t – 90°)

Answer: Option D

Explanation:

Z = jXL = jωL = = 1∠90° and V = IXL

Question: In the circuit of figure
[A].

Va would always lag Vb

[B].

Va would always lead Vb

[C].

Va and Vb can be in phase

[D].

phase angle between Va and Vb would always be 90°

Answer: Option B

Explanation:

Voltage across inductance leads the current and voltage across capacitance lags the current.

Question: For a series circuit of R and variable XL the admittance locus is
[A].

a semicircle in first quadrant

[B].

a semicircle in fourth quadrant

[C].

a straight line in first quadrant

[D].

a straight line in fourth quadrant

Answer: Option B

Explanation:

No answer description available for this question.

Question: For a series circuit of variable R and XL, the impedance locus is
[A].

a straight line parallel to X axis in first quadrant

[B].

a straight line parallel to X axis in fourth quadrant

[C].

a straight line parallel to Y axis in second quadrant

[D].

a straight line parallel to Y axis in first quadrant

Answer: Option A

Explanation:

No answer description available for this question.

Question: A variable resistance R and capacitive reactance XC are fed by an voltage. The current locus is
[A].

a semi circle in 4th quadrant

[B].

a semi circle in first quadrant

[C].

a straight line in 4th quadrant

[D].

a straight line first quadrant

Answer: Option B

Explanation:

No answer description available for this question.

Question: A variable resistance R and capacitive reactance XC are connected in series. As R is varied, the locus of Z is
[A].

a straight line parallel to Y axis in 4th quadrant

[B].

a straight line parallel to X axis in 4th quadrant

[C].

a straight line parallel to Y axis in second quadrant

[D].

a straight line parallel to Y axis in first quadrant

Answer: Option C

Explanation:

No answer description available for this question.

Question: In a series RLC circuit the phase angle θ of impedance Z ∠θ is positive. The circuit will behave as
[A].

resistive circuit

[B].

RC circuit

[C].

RL circuit

[D].

either RL or RC circuit

Answer: Option B

Explanation:

In RL circuits phase angle of Z is positive.

Question: In figure the switch has been in position 1 for a long time. At t = 0, the switch is moved to position 2. The equation for transient current is
[A].

[B].

[C].

[D].

Answer: Option C

Explanation:

When switch is in position 2, time constant is