DieselShip's Online Content Library

Q8. Derive the formula for total resistance of a circuit containing 3 resistors in

a) Series (8)

b) Parallel (8)

Q2. a) What are the protections provided for the electrical equipment of ship's steering gear? (8)

b) Describe steering gear tests and drills? (8)

Q3. (a) Sketch and describe the working of a Lead-Acid battery. (12)

(b) What routine maintenance is carried out on these batteries? (4)

Q4. a) How is the Synchroscope connected for paralleling operation of alternator? (8)

b) Explain lamp bright method used to paralleling alternators. (8)

Q5. a) What is high voltage and what are the high voltage equipment? (6)

b) Briefly explain the safety requirements of high voltage system. (10)

Q6. a) State Ohm's Law. (3)

b) State the limitations of Ohm's Law. (3)

c) 3 resistors of value 2 Ω, 4 Ω and 8 Ω are connected in series across a supply of 42 V. Find the current taken from supply and voltage drop across each resistor. (10)

Q7. a) What is the difference between a DC Generator and a DC motor? (6)

b) A 4-pole, 32 conductor, Lap-wound DC shunt generator with terminal voltage of 200 V delivering 12 A to the load has ra = 2 and field circuit resistance of 200 Ω. It is driven at 1000 RPM .

a) Calculate the flux per pole in the machine. (6)

b) If the machine has to be run as a motor with the same terminal voltage and drawing 5 A from mains, maintaining the same magnetic field, find the speed of the machine. (10)

Q8. a) Describe in detail the method used to measure the capacitance of a capacitor.(6)

b) A circuit has a resistance of 3R and an inductance of 0.01 H. The voltage across its ends is 60V and the frequency is 50Hz. Calculate (a) the impedance. (b) the power factor (c) the power absorbed.(10)

Q9. a) Explain Fleming's Right hand rule. (6)

b) A one-turn armature coil has an axial length of 0.4m and a diameter of 0.2m. It is rotated at a speed 500 rev/min in a field of uniform flux density of 1.2 T. Calculate the magnitude of the e.m.f. induced in the coil. (10)