Question 1 |

The transfer function of a real system, H(s), is given as:

H(s)=\frac{As+B}{s^2+Cs+D}

where A, B, C and D are positive constants. This system cannot operate as

H(s)=\frac{As+B}{s^2+Cs+D}

where A, B, C and D are positive constants. This system cannot operate as

low pass filter. | |

high pass filter | |

band pass filter. | |

an integrator. |

Question 1 Explanation:

Put s=0, H(0)=\frac{A \times 0+B}{0+C \times 0+D}=\frac{B}{D}

So, the system pass low frequency component. Put s=\infty , H(\infty )=0

For high pass filter, high frequency component should be non zero. Hence this system cannot be operated as high pass filter.

So, the system pass low frequency component. Put s=\infty , H(\infty )=0

For high pass filter, high frequency component should be non zero. Hence this system cannot be operated as high pass filter.

Question 2 |

For an ideal MOSFET biased in saturation, the magnitude of the small signal
current gain for a common drain amplifier is

0 | |

1 | |

100 | |

infinite |

Question 2 Explanation:

For ideal MOSFET, i_G=0

Therefore, Current gain, A_I=\frac{i_s}{i_G}=\infty

Therefore, Current gain, A_I=\frac{i_s}{i_G}=\infty

Question 3 |

The most commonly used relay, for the protection of an alternator against loss of
excitation, is

offset Mho relay. | |

over current relay. | |

differential relay | |

Buchholz relay. |

Question 4 |

The geometric mean radius of a conductor, having four equal strands with each strand
of radius 'r', as shown in the figure below, is

4r | |

1.414r | |

2r | |

1.723r |

Question 4 Explanation:

Redraw the configuration:

\therefore \; GMR=(r' \times 2r\times 2r\times 2\sqrt{2}r)^{1/4}

Where, r'=0.7788r

Hence, GMR=1.723r

\therefore \; GMR=(r' \times 2r\times 2r\times 2\sqrt{2}r)^{1/4}

Where, r'=0.7788r

Hence, GMR=1.723r

Question 5 |

The valid positive, negative and zero sequence impedances (in p.u.), respectively, for
a 220 kV, fully transposed three-phase transmission line, from the given choices are

1.1, 0.15 and 0.08 | |

0.15, 0.15 and 0.35 | |

0.2, 0.2 and 0.2 | |

0.1, 0.3 and 0.1 |

Question 5 Explanation:

We have,

X_0 \gt X_1=X_2

(for 3-\phi transposed transmission line)

X_0 \gt X_1=X_2

(for 3-\phi transposed transmission line)

There are 5 questions to complete.