1. Fill in the blanks. Choose the correct answers from the choices given below:

(risers, lines, reactive, short circuit, frequency, humidity, maintenance, survey, steel, interlock, tap, conservator, creepage, forced, delta)
ABT is dependent.

(ii) Quality of SF6 gas is checked by its content.

(iii) The basic grounding system is in the form of earth mat with An is provided between isolator and earth switch. Bus voltage is controlled by changing transformer

(vi) In ACSR conductor, central core is of Before installation of line, needs to be carried out.

(viii) Earthing switches are provided at various locations to facilitate is provided for provision of expansion and contraction of oil in the transformer. Primary of transformer winding is generally connected in

(xi) An insulator is specified by its distance.

(xii) Large transformers require oil cooling.

(xiii) Surge arrester is installed. for protection of switchgear, transformer and
(xiv) Circuit breaker can interrupt large current.

(xv) compensation is provided by shunt capacitors in a sub-station.

2. Write True or False for the statements given below: Isolators cannot be operated" unless the corresponding breaker is in closed position.
Resistance of transformer winding is very high.

(iii) The faults on HT lines are far less than compared to LT lines.

(iv) Purified water with low resistance value is used for live line washing.
An MRI is an advanced electronic meter.
For oil fire, foam type extinguishers are used.

(vii) Transformers can change the frequency of electric supply.

(viii) Secondary output current of a CT may be 5 A.
No earth switch can be closed unless the corresponding isolator is in open position. Overloading of a distribution transformer can be detected with the help of Tong tester.

3. Match the following given in Column with Column

Column Column Conductor Relay Multiplying factor XLPE CT Porcelain Cable Sag Bushing Energy meter

Answer any eight questions from the following:

4. Write a brief note on Buchholz relay.

5. Describe about Ring main system.

6. How are the feeders different from a distribution line?,

7. Why is DC system required in a sub-station? How is it provided there?

8. Describe the various measures that can be taken for reducing commercial losses.

9. Differentiate between preventive maintenance and breakdown maintenance.

10. Describe with examples how CT/PT installation can cause significant loss in terms of revenue.

11. What are the advantages of Cable transmission lines with respect to Overhead lines?

12. What are the advantages of HVDS

13. Write a brief note on Static Meters.