Question

What will be the poles of transfer functions \(G(s) = \frac{{1}}{{s(s + 2)}}\)?
1. 0, 2
2. 0, 0
3. 2, -2
4. 0, -2

Answer 1

Correct Answer - Option 4 : 0, -2

Concept:

The standard form of the transfer function is described as:

\(T\left( s \right) = \frac{{K(s + z_1)(s+z_2)......}}{{\left( {s + P_1} \right)\left( {s + P_2} \right)}.......}\)

z1 and z2 are the zeros of the transfer function

P1 and P2 are the poles of the transfer function

Application:

The given transfer function is:

\(G(s) = \frac{{1}}{{s(s + 2)}}\)

For the location of poles, put denominator = 0

s = 0, -2

So, option 4 is correct.

• Zeros are the roots of the transfer function at which the transfer function becomes zero.
• In a transfer function, the frequencies for which the value of the numerator becomes zero are called Zeros.
• Poles are the roots of the transfer function at which transfer function becomes infinity.
• In a transfer function, the frequencies for which the value of the denominator becomes zero are called Poles.