The open-loop transfer function of unity feedback control system is given by G(s)=K/s(s+1) If the gain is increased to infinity, then the damping ratio will tend to became

1.  1/√2

2.  1

3.  0

4.  ∞

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0

Explanation :
No Explanation available for this question

A fault occuring at the terminals of an unloaded synchronous generator opetaing at its rated Voltage has resulted in the following values of the current and voltage. Ia0 = j 2.37 p.u. Ia1 =j 3.05 p.u. Ia2 =j 0.68 p.u. Vao = Va1 = Va2 = j2.37 p.u. The fault that has occurred is

1.  L-L fault

2.  L-L-G fault

3.  L-G fault

4.  none of these

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L-L-G fault

Explanation :
No Explanation available for this question

A second order differential equation is given by d2x/dt2+5 dx/dt+7x=7y The frequency and damping ratio respectively are

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Explanation :
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If the open-loop transfer function is a ratio of a numerator polynomial of degree 'm' and a denominator polynomial of degree 'n' then the integer(n-m) represents the number of

1.  break-away points

2.  unstable poles

3.  seperate root loci

4.  asymtotes

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asymtotes

Explanation :
No Explanation available for this question

Given the relationship between the input u(t) and the output y(t) to be y(t)=∫t0(2+t-)e-3(t-?)u(?)d? The transfer function Y(s)/U(s) is

1.  2e -2s/s+3

2.  s+2/(s+3)2

3.  2s+5/s+3

4.  2s+7/(s+3)2

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2s+7/(s+3)2

Explanation :
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A single line to ground fault occurs on an unloaded generator in phase a. If xd = x2 = 0.25 p.u., xo =- 0.15 p.u., reactance connected in the neutral, Xn = 0.05 p.u. and the initial prefault voltage is 1.0 p.u., then the magnitude of the fault current will be

1.  3.75 p.u.

2.  1.54 p.u.

3.  1.43 p.u.

4.  1.25 p.u.

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3.75 p.u.

Explanation :
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The transfer function d(s) to y(s) is

1.  2/3s+7

2.  2/3s+1

3.  6/3s+7

4.  2/3s+6

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2/3s+7

Explanation :
No Explanation available for this question

In a large interconnected power system, consider three buses having short-circuit capacity,1500 MVA (1), 1200 MVA (2) and 1000 MVA (3) respectvily. The voltage of all the buses al e 1.0 p.u. If a 3-phase fault takes place on bus 2, the change in bus voltage is described as

1.  ΔV1>ΔV2 >ΔV3

2.  ΔV1

3.  ΔV1 >ΔV3 >ΔV2

4.  none of these

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ΔV1 <ΔV3 <ΔV2

Explanation :
No Explanation available for this question

The addition of open loop zero pulls the root-loci towards

1.  the left and therefore system becomes more stable

2.  the right and therefore system becomes unstable

3.  imaginary axis and therefore system becomes marginally stable

4.  the left and therefore system becomes unstable

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the left and therefore system becomes more stable

Explanation :
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For the Nichols plot shows, the system is

1.  unstable

2.  stable

3.  over damped

4.  critically stable

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