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Q6. A. Explain distribution factor and pitch factor for alternator windings.

B. A 3phase, 4pole 24 slot alternator has its armature coils short pitched by one slot. Find the distribution factor and pitch factor.

Q8. A. What is meant by “Resonance” in RLC circuits? Compare the series and parallel resonance circuits.

B. Find the frequency at which the following circuit resonates.

Q7. Two 10 MVA 3 phase Alternator operate in parallel to supply at 0.8 power factor with lagging load of 15 MVA. If the output of one Alternator is 8 MVA at 0.9 lagging. A. Calculate the output of second Alternator. B. Calculate the value of Power factor of second Alternator.

Q7. A. Describe the characteristic of d.c. generator.

B. A d.c. motor takes an armature current of 110 A at 480 V. The resistance of the armature circuit is 0.2 . The machine has six poles and the armature is lap-connected with 864 conductors. The flux per pole is 0.05 Wb. Calculate: (i) The speed; (ii) The gross torque developed by the armature

Q10. a) Describe the various resistances acting against the motion of the ship?

The following data are available from the hydrostatic curves of a vessel.

Calculate the TPC at a draught of 5.05m.

Q9. A. Describe measures which may be taken to improve the stability or trim of a damaged ships.

B. A ship 85m long displaces 8100 tonne when floating in seawater at draughts of 5.25m forward and 5.55m aft. TPC 9.0, GML 96m, LCF 2m aft of midships. It is decided to introduce water ballast to completely submerge the propeller and a draught aft of 5.85m is required. A ballast tank 33m aft of midships is available. Find the least amount of water required and the final draught forward.

Q10. A. Explain what is meant by singing of propeller.

B. A propeller 6m diameter has a pitch ratio of 0.9, BAR 0.48 and, when turning at 110 rev/min, has a real slip of 25% and wake faction 10.30. If the propeller delivers a thrust of 300 KN and the propeller efficiency is 0.65 calculate - i Blade area; ii Ship speed; iii. Thrust power; iv Shaft power v. Torque

Q8. A ship consumes an average of 70 tonne of fuel per day on main engines at a speed of 17 knots. The fuel consumption for auxiliary purposes is 8 tonne per day. When 800 nautical miles from port it is found that only 140 tonne of fuel remains on board and this will be insufficient to reach port at the normal speed. Determine, using a graphical solution, the speed at which the ship should travel to complete the voyage with 20 tonne of fuel remaining.

Q8. (a) Define coefficient of fineness of waterplane area, block coefficient and midships coefficient. (b) A box shaped vessel has length 100m and breadth 12m and floats at a range of drafts from 1m to 10m. Produce curves of KB1, BM and KM.

Q8. A. Describe the fundamental principle of a propeller. B.A propeller 6m diameter has a pitch ratio of 0.9, BAR 0.48 and, when turning at 110 rev/min, has a real slip of 25% and wake faction 0.30. If the propeller delivers a thrust of 300 KN and the propeller efficiency is 0.65. Calculate - i Blade area; ii Ship speed; iii. Thrust power; iv Shaft power v. Torque

Q9. A. State what is meant by the term floodable length illustrating your answer by drawing a typical curve of floodable length of a ship. B. A vessel has a maximum allowable draught of 8.5m in fresh water and 8.25m in seawater of 1.025/m3, the TPC in the sweater being 27.5. The vessel is loaded in never water of 1.012 t/m2 to a draught of 8.44m. If it now moves into seawater, is it necessary to pump out any ballast and if 50, how much?

Q6. (a). Explain the significance of the root- mean- square value of an alternating current or voltage waveform; Define the form factor of such a wave form.

B. Draw the circuit of Half-wave rectifier and its output waveform. A diode whose internal resistance is 20𝛀 is to supply power to 1000 𝛀 load from 110 V (RMS) source. Calculate

(i) peak load current, (ii) DC load current, (iii) AC load current.