Results for gate 2016

Electrical Machines solved Questions-Gate 2016

January 18, 2016
MCQ 4.1 The slip of an induction motor normally does not depend on
(A) rotor speed (B) synchronous speed
(C) shaft torque (D) core-loss component

MCQ 4.2 A 220 V, 15 kW, 100 rpm shunt motor with armature resistance of 0.25 Ω,
has a rated line current of 68 A and a rated field current of 2.2 A. The
change in field flux required to obtain a speed of 1600 rpm while drawing a
line current of 52.8 A and a field current of 1.8 A is
(A) 18.18% increase (B) 18.18% decrease
(C) 36.36% increase (D) 36.36% decrease

MCQ 4.3 The locked rotor current in a 3-phase, star connected 15 kW, 4 pole, 230 V, 50 Hz induction motor at rated conditions is 50 A. Neglecting losses and magnetizing current, the approximate locked rotor line current drawn when the motor is connected to a 236 V, 57 Hz supply is
(A) 58.5 A (B) 45.0 A
(C) 42.7 A (D) 55.6 A

MCQ 4.4 A single phase 10 kVA, 50 Hz transformer with 1 kV primary winding draws 0.5 A and 55W, at rated voltage and frequency, on no load. A second transformer has a core with all its linear dimensions 2 times the corresponding dimensions of the first transformer. The core material and lamination thickness are the same in both transformer. The primary winding of both the transformers have the save number of turns. If a rate voltage of 2 kV at 50 Hz is applied to the primary of the second transformer, then the no load current and power, respectively, are
(A) 0.7 A, 77.8 A (B) 0.7 A, 155.6W
(C) 1A, 110W (D) 1A, 220W

MCQ 4.5 A 4 point starter is used to start and control the speed of a
(A) dc shunt motor with armature resistance control
(B) dc shunt motor with field weakening control
(C) dc series motor
(D) dc compound motor


                                                                      ANSWERS


Answers will be updated soon....
Electrical Machines solved Questions-Gate 2016 Electrical Machines solved Questions-Gate 2016 Reviewed by Sikha on January 18, 2016 Rating: 5

Gate 2016 preparation-Signals and Systems

January 01, 2016
·         Continuous and Discrete Time Signals
  • We  need to study here the impact of shifting and scaling operations on the waveform of the signals, Refer in  in Oppenheim book.
  •  classifications of signals based on different criteria like:
a)      Periodic and Aperiodic Signal
b)      Even and Odd Signal
c)      Power and Energy Signals


  • Linear Time Invariant Systems
This is the most important part in Signals and Systems .
  • impulse response -The impulse response is useful when there is a connection of more than one systems like  in cascade configuration or parallel one but you need to remember the equivalent impulse response of thesystem.
  • convolution methodology
by the help of convolution we can compute output at some points only and verify with the options given and save time.
  • properties of Systems like
a)      Causality,
b)      Time-Invariance,
c)       Stability,
d)     Linearity
e)      and we need to study the criterion to determine each of these properties for a system
  • Fourier Series
  • two types of Fourier Series and Transforms  for Continuous Time Signals and other for Discrete Time Signals. for EEE GATE course discrete time Fourier Series is not included and hence they only need to prepare only continuous time fourier series.
Need to remember two things or rather three things which are:
  • Analysis and Synthesis Equations
  • Properties of Transforms
  • Common Transform Pairs
Fourier Transform
  • need to remember that Fourier Transform exists for Aperiodic Signals
  • Fourier Series for Periodic Signals
  • Fourier Transform approaches Fourier Series for periodic Signals.

Also, one more important thing is the fourier transform of rectangular and triangular functions and the converse also which can easily be computed using duality property.
Laplace Transform
  • Laplace Transforms only exist for Continuous Time
  • The concept of Region of Convergence (ROC) as the same transform may have different inverses based on different ROCs.
  • no Laplace Transform is complete without
  • the concept of Initial Value and Final Value Theorem
  • Before applying final value theorem, please verify the stability.
Z-Transform
  • Z-Transform is for the discrete time signals
  • some striking differences also like in case of Final Value Theorem
  • the concept of Stability and Causality
  • pole-zero plot is given and system properties need to be identified.
Sampling

  • important concept in Sampling is for the Nyquist Rate and Nyquist Frequency
  • practice drawing one or two waveforms where sampling frequency is less than Nyquist Frequency
  • Band-Pass Sampling Theorem as that may also be asked.
Gate 2016 preparation-Signals and Systems Gate 2016 preparation-Signals and Systems Reviewed by Sikha on January 01, 2016 Rating: 5

Gate Preparation- Power Systems

December 08, 2015
The major topics in Power Systems for Gate 2016 are as follows:
The major topics in Power Systems for Gate 2016 are as follows:
A. Transmission and Distribution
1.     overhead transmission lines 
·           memorize the expressions for Inductance and Capacitance for both Single Phase and Three Phase Lines. 
·          practice some problems based on this which involve the computation of GMD and GMR.
2.      modelling of Short and Medium Transmission Lines 
·         Long Transmission Lines is not much important in Steady State Analysis and Short Transmission Line is most important.
·         A,B,C,D Parameters of the line 
·         power expressions in terms of A,B,C,D 
·         approximate voltage regulation in Short Transmission Line which is same as Transformer.
3.      Surges 
1.        memorize the thevenin equivalent circuit for analysis of surges to calculate the Transmission and Reflection Coefficient for Voltage
2.       Voltage Control and Power Factor Correction
4. UG Cables
1.       insulation resistance
3.       capacitance model for 3 phase  3 core belted cable which has core capacitance and sheath capacitance.

4.      Overhead Insulator
    1.  voltage distribution across different discs can be asked
    2. remember the expression upto 3 discs.

6.       Distribution Systems
    1. applying KVL and finding the currents in different branches.

you can find the Solved question papers of Gate (from 2000 to 2015) Electrical HereGATE - Electrical Engineering 2016 : Solved Papers 2000 - 2015 (English) 13th Edition 
Gate Preparation- Power Systems Gate Preparation- Power Systems Reviewed by Sikha on December 08, 2015 Rating: 5
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