1.
The use of high speed circuit breakers

A

Reduces the short circuit current

B

Improves the system stability

C

Decreases the system stability

D

Increase short circuit current

Answer/ Hint

2.
Transient state stability is generally improved by

A

Using high speed governors on machines

B

Using low inertia machines

C

Dispensing with neutral grounding

D

Any of the above

Answer/ Hint

3.
Load flow study is carried out for

A

Load-frequency control

B

Planning of power system

C

Fault calculations

D

Study of stability of the system

Answer/ Hint

4.
Load flow studies must be made on a power system before

A

Making short-circuit studies but not for transient stability studies on the power system.

B

Making transient stability studies but not for short-circuit studies on the power system.

C

Making both short-circuit and transient stability studies on the power system.

D

For neither Making short-circuit studies nor transient stability studies on the power system.

Answer/ Hint

5.
Load flow studies involve solving simultaneous

A

Linear algebraic equations

B

Non-Linear algebraic equations

C

Linear differential equations

D

Non-Linear differential equations

Answer/ Hint

6.
In load flow studies of a power system, a voltage control bus is specified by :

A

Real power and reactive power

B

Reactive power and voltage magnitude

C

Voltage and voltage phase angle

D

Real power and voltage magnitude

Answer/ Hint

7.
For a load-flow solution the quantities normally specified at a voltage controlled bus are

A

P and Q

B

P and |V|

C

Q and |V|

D

P and

Answer/ Hint

8.
At slacks bus, which one of the following combinations of variables is specified ?

A

|V|,

B

P, Q

C

P, |V|

D

Q, |V|

Answer/ Hint

9.
In a power system, the maximum number of buses are

A

Generator buses

B

Load buses

C

Slack buses

D

P-V buses

Answer/ Hint

10.
If a voltage controlled bus is treated as a load bus, then which one of the following limits would be violated ?

A

Voltage

B

Active power

C

Reactive power

D

Phase angle

Answer/ Hint

11.
In load-flow analysis, the load connected at a bus is represented as

A

Constant current drawn from the bus.

B

Constant impedance connected at the bus.

C

Voltage and frequency dependent source at the bus.

D

Constant real and reactive power drawn from the bus.

Answer/ Hint

12.
The voltage of a particular bus can be controlled by controlling

A

Phase angle

B

Reactive power of the bus

C

Active power of the bus

D

Phase angle and reactive power

Answer/ Hint

13.
Gauss-Seidel interactive method can be used for solving a set of

A

Linear differential equations only

B

Linear algebraic equations only

C

Both Linear and nonlinear algebraic equations

D

Both Linear and nonlinear differential equations

Answer/ Hint

14.
Fault calculation using computer program are usually done by

A

method

B

method

C

Both of the above

D

None of the above

Answer/ Hint

15.
The Gauss Siedel load flow method has following disadvantages. Tick the incorrect statement

A

Unreliable convergence

B

Slow convergence

C

Choice of slack bus affects convergence

D

A good initial guess for voltages is essential for convergence

Answer/ Hint

16.
In Gauss-Seidal load flow method, the number of iterations may be reduced if the correction in voltage at each bus is multiplied by

A

Gauss constant

B

Acceleration factor

C

Blocking factor

D

Lagrange multiplier

Answer/ Hint

17.
Compared to Gauss Siedel method, Newton-Raphson method takes

A

Less number of iterations and more time per iterations .

B

Less number of iterations and less time per iterations .

C

More number of iterations and more time per iterations .

D

More number of iterations and less time per iterations .

Answer/ Hint

18.
Regulating transformers are used in power system for control of

A

Voltage

B

Power factor

C

Power flow

D

All of the above

Answer/ Hint

19.
In a load-flow study a PV bus is treated as a PQ bus when

A

Voltage limit is violated

B

Active power limit is violated

C

Phase angle is high

D

Reactive power limit is violated

Answer/ Hint

20.
If the reference bus is changed in two load flow buses with same system data and power obtained for reference bus taken as specified P and Q in the latter run

A

The system losses will be unchanged but complex bus voltages will change.

B

The system losses will change but complex bus voltages remain unchanged.

C

The system losses as well as complex bus voltages will change.

D

The system losses as well as complex bus voltages will be unchanged

Answer/ Hint