DieselShip's Online Content Library

Q1. What is Zener diode and how does it regulate the voltage? What happens to the series current, load current and Zener current when the d.c input voltage of a Zener regulator increases? Draw a neat diagram of Zener regulator and explain. (16)

Q5. Explain with the help of a neat diagram the operation of a brushless alternator. What would likely happen if one of the rotating Diode fails and becomes: (16)

a) An open circuit?

b) A short circuit?

Q3. Draw and explain the working of a synchroscope. How could you monitor the correct instant for synchronizing without the aid of a synchroscope.

Q1. With Respect to PLC’s used onboard ships:

a) Draw and explain the block diagram of a PLC. (8)

b) Name the onboard ship equipment where PLC’s are used. (4)

c) What are the advantages of PLC controllers over other type of controllers? (4)

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)

Q4. (a) Explain the principle of a Transformer? Discuss the various types of transformers used onboard? (8)

(b) In a container ship, a 3-ph, delta/delta connected 6600/440 V, 60 Hz transformer is feeding AMP supply from shore to 440 Volt switchboard. Transformer primary current takes a line current of 100 amp, when secondary load of 0.8 lagging p.f. is connected. Determine each coil-current and KW output of transformer. (8)

Q7. How will you fight a fire in a galley? How will you at least restrict the fire if you are the first person to sight the fire in the galley? (16)

Q7. a) Describe the routine tests required for self-contained breathing apparatus sets (8)

b) Describe the procedure to be adopted to find missing personnel in a smoke-filled accommodation area. (8)

Q9. With reference to MARPOL Annex I:

a) Draw a 15 ppm oily water separator and explain the principles of operation (8)

b) Periodical maintenance and checks tests required to be done to verify the effectiveness of the above system. (8)