POWER SYSTEM

HERE ARE SOME IMPORTANT QUESTION OF POWER SYSTEM RELATED TO CSEB EXAMINATIONS

1. A SYSTEM IS SAID TO BE EFFECTIVELY GROUNDED IF ITS:

A. RATIO OF X0:X1> 3

B. RATIO OF X0:X1> 2

C. RATIO OF X0:X1> 1.5

D. RATIO OF X0:X1< 3

ANS. D

2. IF THE NORMAL SYSTEM FREQUENCY IS 50 Hz and IF IT IS OPERATING AT 53 Hz THEN THE EQUIPMENT ON THE SYSTEM MOSTLY AFFECTED IS:

A. TURBINE

B. ALTERNATOR

C. POWER TRANSFORMER

D. NONE

ANS. TURBINE

3. AN IMPEDENCE OF (40+j30)OHMS CARRIES A CURRENT OF 10 A .THE REAL AND REACTIVE POWER CONSUMED BY THE IMPEDENCE RESPECTIVLY ARE:

A. 4 KW, 3 KVAR

B. 3 KW, 4 KVAR

C. 8 KW, 6 KVAR

D. NONE

ANS. 4 KW , 3 KVAR

SOLUTION -

WE KNOW THAT POWER CONSUMED IS GIVEN BY I*I*R

HENCE REAL POWER OR ACTIVE POWER = 10*10* 40 = 4 KW

REACTIVE POWER = 10*10* 30 = 3 KVAR

4. THE MAIN ADVANTAGE OF USING GRID SYSTEM IS

A. FEWER GENERATORS ARE REQUIRED AS RESERVE

B. FEWER GENERATORS ARE REQUIRED AS SPINNING RESERVE

C. MOST ECONOMICAL PLANT IS USED AT TIME OF LOW DEMAND

D. ALL OF THE ABOVE

ANS. D

5. THE IMPEDENCE OF A CIRCUIT IS GIVEN BY Z= (3+j4) OHM ; ITS CONDUCTANCE IS

A. 1/3

B. 3/5

C. 3/25

D. 4/5

ANS.C

SOLUTION-

CONDUCTANCE = 1/ IMPEDANCE =1/(3+j4) = 3/25

6.The Maximum Rating Of Power Factor Can Be:

A. 1.0

B. 0.9

C. 0.98

D. 0

7. In A Balanced Three Phase Four Wire Ac System Three Phase Sequence Is Ryb. If The Voltage Of  R Phase Is 230 The Voltage Of B Phase Will Be

A. 400

B. 230

C. 440

D. 220

CSEB EXAM

HERE I SOME IMPORTANT INFORMATION RELATED TO CHHATTISGARH STATE ELECTRICITY BOARD EXAMS 2010-

1. THERE WILL BE 100 QUESTIONS OUT OF WHICH 50 QUESTION ARE RELATED TO TECHNICAL PART AND REMAINING 5O RELATED TO NON TECHNICAL PART.

2. THE PAPER WILL BE OF TWO HOURS .

3. NO CALCULATOR OR ELECTRONIC GADGETS ALLOWED IN THE EXAMINATION .

4. PAPER WILL BE MOSTLY RELATED TO POWER SYSTEM PROTECTION, ELECTRICAL MACHINES , POWER ELECTRONICS , SWITCHGEARS , CONTROLL SYSTEMS ETC