JNTU Kakinada B-Tech 2-2 RT22024 POWER SYSTEMS – I R13 April 2018 Question Paper

Code No: RT22024
II B. Tech II Semester Supplementary Examinations, April-2018
POWER SYSTEMS – I (Electrical and Electronics Engineering)Time: 3 hours Max. Marks: 70
Note: 1. Question Paper consists of two parts (Part-A and Part-B) 2. Answer ALL the question in Part-A
3. Answer any THREE Questions from Part-B
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PART ?A
1. a) What are the factors to be consider for selection of site for a thermal power plants
b) What is mean by nuclear fission
c) How the distribution systems are classified
d) Contrast between indoor and outdoor substations
e) Derive the expression for power factor of cable
f) Which information you can obtained from load duration curve
PART ?B
2. a) What are the functions of economizer and super heater in a thermal power plant?
b)What are the types of cooling towers and discuss each type of cooling tower with
schematic diagram.

3. a) Discuss the internal hazards due to radiations
b) What are the types of nuclear reaction? Describe briefly

4. a)What is the importance of load p.f. in AC distribution
b) A 300 m distributor fed from both ends F
1
and F
2
is loaded uniformly at the rate of
2 A/m run. The resistance of loop is 0.2 O/km. Find the minimum voltage and the
point where it occurs, if the feeding points F
1
and F
2
are maintained at 225 V and
220 V respectively. Also find the currents supplied from the feeding points F
1
and
F
2
.

5. a) Classify various types of substations according to service requirements and
explain
b) Discuss the installation and maintenance of gas insulated substations.

6. a) Show that for the same dimensions of a cable with an intersheath can withstand a
working voltage of 33% higher than a non-intersheath cable. Assume same
homogeneous dielectric and most economical designs for both cables
b) For the cable shown above, it is given that R
1
= 3 cm, R
3
= 1.2cm, and R
2
=1.5 cm.
Find the maximum electric field for an operating voltage of 12.5 kV (i) with
capacitance grading and (ii) without capacitance grading.

7. a) Discuss the different classifications of costs of electrical energy.
b) A generating station has the following daily load cycle
Time(hrs) : 0-6 6-10 10-12 12-16 16-20 20-24
Load (MW) : 40 50 60 50 70 40
Draw the load curve and find (i) maximum demand, (ii) units generated per day
and (iii) average load and load factor
1 of 1
SET – 1
R13