DieselShip's Online Content Library

Q1. What are semiconductor devices? What are its advantages over thermionic devices? With respect to semi-conductor devices describe working principle and application of the following;-

 A. Zener Diode,

B. Transistor,

C. Photocell,

D. Thyristor

Q1. With reference to the provision of a shore electrical supply to a ship:

A. Sketch an arrangement for taking A.C. shore supply and checks to be carried out prior taking shore connection?

B. Describe the method of safely connecting the arrangement sketched in (A) to the shore Supply?

Q2. A. With respect to measuring instruments what is the difference between analogue and digital measuring instruments. Explain the working principle of each type.

B. Describe with the aid of simple sketches one analogue and one digital measuring instrument you have used onboard.

Q5. With reference to electronic control systems A. Draw a simple block diagram for temperature control B. Describe each component shown in the diagram in (a).

Q2. Tank liquid level sensors are an integral part of ships. Describe with aid of suitable sketches the working principle of,

(a) capacitive type level sensor;

(b) Ultrasonic level sensor;

(c) Float.

Q3. Diesel electric propulsion is now being chosen as the power plant for an increasingly wide variety of vessels.

(a) Sketch a simple layout of such an installation.

(b) Explain the advantages of selecting such a plant.

Q7. With reference to Dynamic positioning systems what do you understand by the term “redundancy”? With the aid of simple block diagrams explain the difference between DP-I, DP-II and DP- III system enumerating their relative advantages and dis advantages.

Q3. The direct online start of squirrel cage motor is used for most electrical drives on a.c. powered ships. Describe with sketches as necessary one method of overcoming each of the following Problems:

A. High starting current; B. Low starting torque.

Q5. With reference to an emergency source of electrical power in cargo ships: -

A. Describe a typical power source.

B. Give a typical list of essential services, which must be supplied simultaneously;

C. Explain how the emergency installation can be periodically tested.