Tripura University 2010 Diploma Electrical Engineering %28DEE%29 5th Semester%2C Electrical Engg %28Mid Term%29%2CSub-TRANSMISSION %26 DISTRIBUTION OF POWER%2C Institute of Technology - Question Paper

TRANSMISSION & DISTRIBUTION OF POWER
third Year (Electrical)
5th Semester, Diploma Electrical Engineering

Time- 1/2 Hrs Full Marks-15

Group-B
ans ques. No. one and 2 from the rest.

1. select the accurate ans from the provided alternatives[Marks 3x1=3]
a) Power factor is describe as_________.
(i)KVA/KW, (ii)KW/KVA, (iii)VI/Watt, (iv)KVAR/KVA

b) Service connection is provided from____
(i)feeder, (ii)Distribution, (iii)either from feeder or distribution, (iv)from none of them

c) The size of feeder is based on ____
(i)Voltage, (ii)Voltage drop, (iii)Current carrying capacity, (iv) frequency.


2. a) explain the term voltage regulation and transmission efficiency as applied to transmission line.[Marks 2]

b) An overhead 3-phase transmission line delivers 5000Kw and 22KV at 0.8 p.f. lagging. The resistance and reactance of every conductor is 4? and 6? respectively.Determine---
(i)Sending end voltage, (ii)Percentage regulation,(iii)Transmission efficiency.[Marks 4]

3. a) State the advantage of low power factor.
b) A synchronous motor improves the power factor of a load of 250KW from 0.8 lagging to 0.95 lagging.Simultaneously the motor carries a load of 80kw.Find-(i)the leading KVAR taken by the motor,(ii)KVA rating of the motor,(iii) power factor at which the motor operates.[Marks 2+4=6]

4. a) describe the terms----(i)feeder,(ii) Distribution.[Marks 2]
b) A single phase a.c distribution AB is fed from end A and has a total impedance of (0.1+j0.2)ohm. At the far end, the voltage Vb=240v and the currents 1000A at a p.f. of 0.8 lagging.At the mid point M, a current of 150A is tapped at a p.f of 0.6 lagging with reference to the voltage at the far end.Calculate the supply voltage VA and phase angle ranging from VA and VB.[Marks 4]

Earning:   Approval pending.