Electronics And Communication Engineering

Question: A wave trap is a
[A].

series tuned circuit

[B].

a parallel tuned circuit

[C].

either a series tuned circuit or parallel tuned circuit

[D].

none of the above

Answer: Option B

Explanation:

It has R and L in one branch and a variable capacitance in second branch.

Question: A resistance R, inductance L and capacitance C are in series. The source frequency is adjusted to be equal to resonant frequency. The lower half power frequency is ω1. Another resistance R is added in series with the circuit. The new lower half power frequency will be
[A].

ω1

[B].

less than ω1

[C].

more than ω1

[D].

either more than ω1 or less then ω1

Answer: Option C

Explanation:

As R increases, Q decreases, bandwidth = . Therefore, bandwidth increases. Hence lower half power frequency will be less than ωr.

Question: A coil of resistance R and inductance L has a capacitor C in parallel with it. The source frequency is adjusted to a value equal to resonant frequency. Another capacitor C is added in parallel with the above circuit, the source current will
[A].

increase

[B].

decrease

[C].

remain the same

[D].

may increase or decrease

Answer: Option B

Explanation:

The circuit will not in resonance. In parallel resonant circuit the current is minimum at resonance. Therefore, current will increase.

Question: A two branch parallel resonant circuit has a coil of resistance R and inductance L, in one branch and a capacitors C in the other branch. The source voltage is V, At resonance the circulating current is
[A].

[B].

[C].

[D].

Answer: Option D

Explanation:

No answer description available for this question.