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)

Q2. a) Briefly explain the principle of Operation of induction Motors (4)

b) What is slip for an induction motor? (4)

c) Draw a simple ladder logic diagram of star delta starting of an induction motor. (8)

Q3. With Respect to Insulated and Earthed Neutral Systems used on board:

a) Discuss the Advantages and Disadvantages of both Insulated and Earthed Systems used on board. (8)

b) What is earth fault and how do you identify Earth fault in the 440 V system onboard. (4)

c) Discuss the consequences of earth fault in an earthed distribution system. (4)

Q4. With the aid of suitable line diagrams, sketch and describe a suitable (MGPS) Marine growth protection system installed on vessels to prevent fouling of internal sea water system mention the important precautions, if any while handling the system. (16)

Q5. a) Which has the greater equivalent resistance; two equal capacitors in series or in parallel? Explain with reasons? (6)

b) A circuit has a resistance of 3Ω inductance of 0.01H. The voltage across its end is 60V and the frequency is 50Hz. Calculate

a) the impedance

b) the power factor

c) the power absorbed. (10)

Q6. Two 220 V d.c. generators each having linear external characteristics, operated in parallel. One machine has a terminal voltage of 270 V on no load and 220V at a load current of 35 A, while the other has a voltage of 280 V at no load and 220V at 50 A. Calculate the output current of each machine and the bus bar voltage when the total load is 60 A. what is the kW output of each machine under this condition. (16)

Q7. (a) As per Annex II of MARPOL. Describe categories in which substances are divided. (8)

(b) Give conditions under which they can be discharged outside special areas? (8)

Q8. With reference to “ISM code” write short notes on. (16)

a) Management Review

b) Advantage of drills and procedure

c) Master overriding authority.

d) Advantage of internal audit.

Q9. a) Sketch and describe a total flooding CO₂ gas system suitable for the protection of machinery spaces. (6)

b) State, with reasons, which valve should be operated first in the system shown in (a) (4)

c) State the periodic maintenance required on the system. (6)