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Q2. a) Briefly Explain Intrinsically safe circuit and Explosion proof circuit. (6)

b) What is EXD and EXI? Where they are used onboard ship. (3)

c) What all Intrinsically safe equipment used on Deck, explain how they are Intrinsically safe. (3)

d) What is Zener Barrier? How flame and explosion contained inside the enclosure. (4)

Q1. a) State essential electrical services on board that are able to be operable under fire conditions. (5)

b) Explain how electric cables for the essential services in part (a) pass through bulkheads whilst maintaining gas tight and watertight integrity. (5)

c) State the requirements for the cables which supply electrically driven emergency fire pumps. (6)

Q3. a) What are safeties incorporated in ACB of ship’s generator and prime mover? (10)

b) Explain the procedure to test reverse power relay (6)

Q7. With Reference to Electrical Safety onboard a vessel:

a) Write Short note on “Electric Shock” (6)

b) Enumerate the relation between Shock Current Levels, the Applied Voltage and the Body resistance. (5)

c) How do you treat a person who has suffered an electric shock onboard from a AC supply? (5)

Q8. With Reference to Electrical Safety onboard a vessel:

a) Write Short note on “Electric Shock” (6)

b) Enumerate the relation between Shock Current Levels, the Applied Voltage and the Body resistance. (5)

c) How do you treat a person who has suffered an electric shock onboard from a AC supply? (5)

Q3. (a) State FIVE essential electrical services that should be operable under fire conditions. (8) (b) Explain how electric cables for the essential services in part (a) pass through bulkheads whilst maintaining gas tight and watertight integrity. (4)

(c) State the requirements for the cables which supply electrically driven emergency fire pumps. (4)

Q3.a) How protection is provided for electrical short circuit. (4)

b) Describe the construction and operation of HRC fuses? (8)

c) What are the advantages of HRC fuses. (4)

Q3. (a) Describe the principle of operation of EACH of the following detecting elements: (8)

(i) Bi-metal strips

(ii) Thermistors

(b) Explain, with the aid of sketches, typical applications where the devices described in (a) may be employed in high voltage electrical systems. (8)

Q1. a) What is intrinsic electric safety? Discuss the specific maintenance protocols, inspections, and safety measures required to ensure the reliability and safety of such equipment on board ship. (8)

b) Describe intrinsically safe equipment used on board ship. (8)

Q8. A) (i) Discuss the various hazards and problems which are associated with electric cable insulation in the event of fire (4)
ii) Suggest remedies for these problems. (4)
B) State how the spread of fire may be reduced by the method used for installing electric cables. (8)

Q2. It is proposed to operate a bow thrusters’ unit from a 3.3 KV electrical supply online suitable option for the design of installation under each of the following heading.

a) Protection of main switch board:

b) Overload of a bow thrusters motor:

c) Cable Protection. (16)

Q3. a) What are the causes of overheating of an induction motor? (4)

b) What preventive measures are provided against damage to an induction motor in installed condition? (3)

c) What is the purpose of “fuse back up protection” provided to an induction motor? (3)

d) How does an induction motor develop torque? (3)

e) What is the condition to be satisfied for achieving maximum running torque in an induction motor? (3)