Electronics and Communication Engineering - Networks Analysis and Synthesis

21.
Three resistances of 15 Ω, 10 Ω and 3 Ω are connected in parallel. The overall resistance is
less than 3 Ω
between 15 and 10 Ω
between 10 and 3 Ω
more than 3 Ω
Answer: Option
Explanation:

For resistances is parallel, overall resistance is less than the smallest resistance.


22.
In figure, the switch is closed at t = 0. At t = 0+ The value of current supplied by battery is
1 A
2 A
zero
infinity
Answer: Option
Explanation:

At t = 0, current in R-L branch is zero.


23.
In the circuit shown in the figure the power dissipated in 30 Ω resistor will be maximum if the value of R is
30 Ω
10 Ω
9 Ω
zero
Answer: Option
Explanation:

If R = 0, it will be act a short circuit, 16 Ω Resistor will not play any role, only power dissipated in 30 Ω resistor.

But it R = 0, then power dissipated in 16 Ω resistor also.


24.
Which of the following polynomials is not Hurwitz?
P1 = s8 + 2s6 + 4s4
P2 = s6 - 3s4 + 2s2 + 1
P3 = s4 + 3s3 + 3s2 + 2s + 1
P4 = s7 + 2s6 2s4 + 4s3 + 8s2 + 8s + 4
Answer: Option
Explanation:

One coefficient is negative. Hence not Hurwitz.


25.
In an RLC underdamped circuit
Answer: Option
Explanation: