95MET-4
Sr. No. 4
EXAMINATION OF MARINE ENGINEER OFFICER
Function: Electrical, Electronic & Control Engineering at Operational Level
MARINE ELECTROTECHNOLOGY
M.E.O. Class IV
(Time allowed - 3hours)
India (2003) Morning Paper Total Marks 100
NB : (1) Answer SIX Questions :
SECTION -1 :- Answer atleast TWO Questions
SECTION -2 :- Answer atleast TWO Questions
(2) All Questions carry equal marks
(3) Neatness in handwriting and clarity in expression carries weightage
(4) Illustration of an Answer with clear sketches / diagrams carries weightage .
SECTION – 1
1.
Explain the meaning of the following terms with reference to automatic control system : -
(a) Control loop
(b) Transmitter
(c) Controller
(d) Desired value.
2. (a) Sketch a Ward-Leonard system for the control of electric motors in deck machinery.
(b) Describe the operation of the system sketched in (a).
3. In process control terminology values which can change without distinct increments, such as temperature, pressure, or level are called ____________.
(a) binary values
(b) digital values
(c) bumpless values
(d) analog values
4.
What is the maximum allowable primary current of a 2 KVA step-down transformer with a four to one turns ratio if connected across a 440 volt line?
(e) 1.1 amps
(f) 4.5 amps
(g) 18.1 amps
(h) 27.7 amps

5.
A lead-acid battery is considered fully charged when the ______________. a.
electrolyte gasses freely b.
battery charger ammeter indicates a positive reading c.
terminal voltage reaches a constant value at a given temperature d.
specific gravity of all cells reaches the correct value and no longer increases over a period of 1 to 4 hours
SECTION – 2
6. A four pole motor is fed at 440 V and takes a armature of 50 A. The resistance of the armature circuit is 0.28

. The armature winding is wave connected with 888 conductors and the useful flux per pole is 0.023 wb. Calculate the speed.
7. Explain the procedure for paralleling of d.c. generator.
A 100 kW, 250 generator is paralleled with a 30 kW, 250 V generator. Both generator have the same voltage regulation. The first generator is supplying a current of 200 A and the other 500 A. What would be the current supplied by each generator if an additional load of
600 A is connected to the bus.
8.
With the help of sketch explain the construction and principle of action of transformer.
Sketch the equivalent circuit of transformer and explain
9.
A 200V, 200kW electric furnace is required to raise 500 kg of brass from an initial temperature of 15°C to the melting point of 910°C. If the overall efficiency is 0.8, calculate the time of the operation. Specific heat capacity of brass is .39 kJ/kg°C.
10. A coil, having an inductance of 0.5H and a resistance of 60

, is connected in series with a
10

F capacitor. The combination so formed is now connected across a sinusoidal supply and it is found that at resonance, the p.d. across the capacitor is 100v. Calculate the current flowing in the circuit under this condition. Sketch the phasor diagram (not to scale)