Monday, September 8, 2014

In a balanced wheatstone bridge, if the position of detecor and source are interchanged, the bridge will still remain balanced. This interference can be drawn from

When the power transferred to the load is maximum, the efficiency of power transfer is


Answer - 50 %

When a reisitors R is connected to a current source, it consumes a power of 18w. When the same R is connected to a voltage source having the same magnitude as the current source, the power absorbed by R is 4.5W. The magnitude of current source and the value of R are

Millman's theorem yields equivalent

A.Impdedance or ResistanceB. Current SourceC. Voltage SourceD. Voltage or Current Source

kirchhof's laws are valid for

  1. Linear Circuits Only
  2. Passive Time Invariant
  3. Non Linear Circuits Only
  4. Both Linear and Non Linear Circuit only

Which of the following theorems is applicable for both linear and non linear circuits?

Three parallel resistive branch are connected across a dc supply. what will be the ratio of the branch currents I1:I2:I3 if the branch resistances are in the ratio R1:R2:R3::2:4:6?

A. 3:2:6
B. 2:4:6
C. 6:3:2
D. 6:2:4

Ideal current source have

Two resistors R1 and R2 give combined resistance of 4.5 ohm when in series and 1 ohm when in parallel the resistance are

A voltage source having an open circuit voltage of 100V and internal resistance of 50W is equivaent to a current source

Which of the following statements is correct? Nichol's chart is useful for detailed study and analysis of

For the equation s3-4s2+s+6=0 the number of roots in the left half of s-plane will be

The bode diagram approach is the most commonly used method for the analysis and synthesis of

A. Non Linear Feedback control system only
B. Linear Feedback Control System Only
C.Open Loop System Only
D. All of the above


The open loop transfer function of a unity feedback control system is given by G(S)=K(S+2)/s(s2+2s+2) the centroid and angles of root locus asymptotes are respectively

Which of the following is the most likely reason for large overshoot in a control system?

  1. High Gain in a System
  2. Presence of dead time delay in a system
  3. High Positive Correcting Torque
  4. High Retarding Torque
Answer : High Positive Correcting Torque

Given a unity feedback system with G(S)=K/s(S+4), the value of k for damping ratio of 0.5 is

The output of first order hold between two consecutive sampling instant is a

How can steady state eror in a system be reduced ?

A. By decreasing the type of system
B. By increasing system gain
C. By decreasing the static error constant
D. By increasing the input

Thursday, August 21, 2014

the type number of control system with G(s)H(s)=K(s+2)/s(s2+2s+3) is

feedback control systems are

For the transmission line which one of the following relations is true?

Which one of the following relays has the capability of anticipating the possible major fault in a transformer?


  1.  Over Current Relay
  2. Differential relay
  3. Buchholz Relay
  4. Over Fluxing Relay

If all the sequence voltages at the fault point in a power system are equal then the fault is a

The gauss siedel load flow method has following disadvantages, tick the incorrect statement

High volatage DC (HVDC) transmission is mainly used for

A. Bulk power transmission over very long distance.

B. Interconnecting two systems with the same nominal frequency.

C. Eliminating reactive power requirement in the operation.

D. Minimizing harmonic at the converter stations.

Keeping in view the cost and overall effectiveness the following circuit breaker is besy suited for the capacitor bank switching

The insulation strength of an EHV transmission line is mainly governed by

A. Load Power Factor
B. Switching Over Voltage
C. Harmonics
D. Corona

Answer : B. Switching Over Voltage

The insulation resistance of a 20 km long underground cable is 8 mega ohm, insulation resisatance for similar cable of 10 km is

For thiven base voltage and base volt amperes, the per unit impedance value of this element is x. The per unit impedance value of this element when the volatage and volt amperes bases are both doubled is

The surge impedence of a 400 km overhead transmission line is 400 ohms. For a 200 km length of the same line, the surge impedance will be