ETO WRITTEN 2024 QUESTION PAPER
QUESTION PAPER
JAN-2024
1 With respect to the High Voltage power systems installation, explain the
different types of circuit breaker that are used, comparing them on merits
and de-merits. Describe the theory of arc phenomenon and the mechanism
fitted to mitigate the arc.
2. Under what conditions, can you produce sustained oscillations? Classify
oscillations with respect to frequency range, principle involved, etc. It is
possible to produce oscillations with RC networks in phase shift oscillator.
Discuss in detail.
3. With reference to the condition monitoring of electrical machinery:
(a) State the important parameters that may be recorded.
(b) Explain how the parameters are measured and what defects may be
revealed.
Section: II
4 (a) Describe the normal criteria used for setting thermal protection relays
and their advantage compared to magnetic types.
(b) The low-voltage release of an a.c. motor-starter consists of a solenoid into
which an iron plunger is drawn against a spring. The resistance of the
solenoid is 350. When connected to a 220V, 50Hz, a.c. supply the current
taken is at first 2A, and when the plunger is drawn into the "full-in" position
the current falls to 0.7A. Calculate the inductance of the solenoid for both
positions of the plunger, and the maximum value of flux-linkages in weber-
turns for the "full- in" position of the plunger.
5. (a) State briefly, the meaning of the expressions 'star-connected' as
applied to three-phase a.c. practice. What is the ratio of the maximum line
voltage to the maximum phase voltage in each case.
(b) Determine the line current taken by a 440V, three-phase, star-connected
motor having an output of 45kW at 0.88(lagging) power factor and an
efficiency of 93 per cent.
6.a) Why is it important to maintain high efficiency of operation and low
values of voltages regulation for power transformers?
(b) A 20KVA, 2000/220V, single-phase transformer has a primary resistance
of 2.1Ω and a secondary resistance of 0.026 Ω. The corresponding leakage
reactance’s are 2.5 Ω and 0.03 Ω. Estimate the regulation at full load under
power-factor conditions of:
(i) unity
(ii) 0.5 (lagging)
(iii) 0.5 (Leading)
Section: IIl
7. Write short notes on following:
(a) Role of Classification Society on ship who act as Recognized Organization.
(b) Enhanced survey program (ESP) and its applicability.
(c) Condition of Class (COC).
8. Name various statutory Certificates and Documents to be carried on board
Chemical Tankers giving reference to the conventions and justify for their
requirement.
9. With respect to the hazardous areas of tankers.
(a) Explain the term flameproof (Ex d) for electrical equipment.
(b) State the type of electrical equipment that would be protected in this
way.
(c) List likely defects of flameproof equipment.
ANSWER
(a) Flameproof (Ex d) for Electrical Equipment:
Flameproof (Ex d) is a type of protection technique used for electrical
equipment operating in hazardous areas where flammable gases, vapors, or
combustible dusts may be present. The term "flameproof" refers to the
ability of the equipment to contain any internal explosion and prevent the
ignition of flammable atmospheres surrounding it. Flameproof equipment
is designed to withstand the pressure and heat generated by an internal
explosion and prevent it from propagating into the surrounding hazardous
area.
The construction of flameproof electrical equipment involves enclosing the
electrical components within a robust and flame-tight enclosure that can
withstand the pressure of an internal explosion. The enclosure is designed
to contain any sparks, flames, or hot gases produced by the explosion,
preventing them from igniting the surrounding flammable atmosphere.
Flameproof enclosures typically have flame paths or pathways designed to
cool and quench any flames or hot gases generated by an internal
explosion. These flame paths are carefully engineered to ensure that they
can withstand the pressure and heat of an explosion without rupturing or
allowing flames to escape.
(b) Type of Electrical Equipment Protected by Flameproof Enclosures:
Various types of electrical equipment used in hazardous areas may be
protected by flameproof enclosures. Some common examples include:
1. Electrical motors and generators
2. Lighting fixtures and fittings
3. Junction boxes and control panels
4. Switches, sockets, and plugs
5. Electrical instrumentation and sensors
6. Communication and signaling devices
These types of equipment are essential for the safe and efficient operation
of tankers and other industrial facilities located in hazardous areas where
the presence of flammable gases or vapors poses a risk of explosion and
fire.
(c) Likely Defects of Flameproof Equipment:
Despite their robust design and construction, flameproof electrical
equipment may experience certain defects or issues that could compromise
their effectiveness in hazardous environments. Some likely defects of
flameproof equipment include:
1. Corrosion: Corrosion of the enclosure or sealing components over
time can weaken the integrity of the flameproof protection, allowing
gases or vapors to penetrate the enclosure and increase the risk of
ignition.
2. Mechanical Damage: Physical damage to the enclosure, such as
dents, cracks, or punctures, can compromise its ability to contain an
internal explosion and prevent the escape of flames or hot gases.
3. Poor Installation: Improper installation or maintenance practices,
such as inadequate sealing of cable entries or incorrect tightening o
fasteners, can create gaps or openings in the enclosure, reducing its
effectiveness as a flame barrier.
4. Aging Components: Deterioration of internal components, such as
seals, gaskets, or flame paths, due to aging or wear and tear, can
reduce the overall reliability and performance of the flameproof
enclosure.
5. Ingress of Contaminants: Ingress of dirt, dust, moisture, or other
contaminants into the enclosure can compromise the integrity of the
flameproof protection and increase the risk of ignition in hazardous
atmospheres.
To mitigate these defects, regular inspection, testing, and maintenance of
flameproof equipment are essential to ensure its continued effectiveness in
hazardous areas. This includes routine checks for corrosion, damage, and
proper installation, as well as adherence to manufacturer's
recommendations and industry best practices for the operation of
flameproof electrical equipment.
FEB-2024
Q1-Compare methods of obtaining speed regulation of three-phase induction
motor generally used in tankers by means of: A. Rotor resistance; B. Cascade
system; C. Pole-changing. Give examples where each system may be
employed with advantage.
Q2-With reference to a 3 speed a.c. cage motor driven cargo winch:
(a) Sketch a circuit diagram for a pole change motor.
(b) Describe how speed change and braking are achieved.
Q3-With reference to preferential tripping in a marine electrical distribution
system.
(a) With the aid of a sketch, describe a typical arrangement to provide three
stages of tripping an instantaneous protection against short circuit.
(b) State why this protection is required
Section: II
Q4 (a) What are the factors which determine the synchronous speed of a
motor?
(b) A total load of 8000 kW at 0.8 power factor is supplied by two alternators
in parallel. One alternator supplies 6000kW at 0.9 power factor. Find the KVA
rating of the other alternator and the power factor.
Q5 (a) List the factors that determine the starting torque of the three-phase
induction motor. How does this torque generally compare with the value of
the rated torque?
(b) The low-voltage release of an a.c. motor-starter consists of a solenoid into
which an iron plunger is drawn against a spring. The resistance of the
solenoid is 35 ohm. When connected to a 220 V, 50 Hz, a.c. supply the current
taken is at first 2 A, and when the plunger is drawn into the "full-in" position
the current falls to 0.7 A. Calculate the inductance of the solenoid for both
positions of the plunger, and the maximum value of flux-linkages in Weber-
turns for the "full- im" position of the plunger.
Q6 (a) With the aid of delta and star connection diagrams, state the basic
equation from which the delta- star and star-delta conversion equation can
be derived.
(b) Three batteries A, B and C have their negative terminals connected
together, between the positive terminals of A and B there is a resistor of 0.5
ohm and between B and C there is a resistor of 0.3 ohm.
Battery A 105 V.
Internal resistance 0.25 ohm
Battery B
100 V.
0.2 ohm
Battery C 95 V. 0.25 ohm
Determine the current values in the two resistors and the power dissipated
by them
Section: III
Q7-What is meant by "Control and Management of Ships ballast water and
sediments" Why is this term so significant with reference to shipping in
recent times.
Q8 (a) State the hazards which may be encountered when entering an
enclosed space and the precautions that should be taken.
(b) Sketch and describe an oxygen analyser which can be used to sample the
atmosphere in void or closed spaces.
(c) Instruction given to person entering the enclosed space as per the ISM
procedures.
Q9 With respect to MARPOL 73/78, Annex-II, Noxious liquid chemicals are
divided into categories;
(a) State the number of categories, and what does each category signify
(b) State the requirement of Procedures and Arrangements Manual, and
what information is available.
ANS-(a) Categories of Noxious Liquid Chemicals:
In MARPOL 73/78, Annex II, noxious liquid chemicals are divided into three
categories based on their potential harm to the marine environment and
human health:
1. Category X: Noxious liquid substances which, if discharged into the
sea from tank cleaning or deballasting operations, are deemed to
present a major hazard to either marine resources or human health
and, therefore, justify the prohibition of the discharge into the marine
environment.
2. Category Y: Noxious liquid substances which, if discharged into the
sea from tank cleaning or deballasting operations, are deemed to
present a hazard to either marine resources or human health or cause
harm to amenities or other legitimate uses of the sea and therefore
justify a limitation on the quality and quantity of the discharge into
the marine environment.
3. Category Z:Noxious liquid substances which, if discharged into the
sea from tank cleaning or deballasting operations, are deemed to
present a minor hazard to either marine resources or human health
and therefore justify less stringent restrictions on the quality and
quantity of the discharge into the marine environment than those
required for Category Y substances.
(b) Requirement of Procedures and Arrangements Manual (P&A
Manual):
According to MARPOL 73/78, Annex II, ships carrying noxious liquid
substances in bulk must have a Procedures and Arrangements Manual
(P&A Manual) on board. The P&A Manual serves as a guide for the crew
regarding the handling, storage, and discharge of noxious liquid substances
to ensure compliance with MARPOL regulations. The manual includes
detailed procedures and arrangements for:
1. Cargo Handling: Safe handling, stowage, and securing of noxious
liquid substances during loading, unloading, and onboard transfer
operations.
2. Tank Cleaning: Procedures for tank cleaning operations, including
pre-cleaning, washing, and rinsing to prevent contamination and
ensure compliance with discharge requirements.
3. Discharge Operations: Guidelines for the safe and environmentally
sound discharge of noxious liquid substances into the sea, including
procedures for ballasting and deballasting operations and
compliance with discharge criteria for each category of substances.
4. Record-keeping: Requirements for maintaining accurate records of
cargo operations, tank cleaning, and discharge activities, including
logbooks and monitoring reports.
5. Emergency Response: Procedures for responding to spills, leaks, or
accidents involving noxious liquid substances, including notification
requirements, containment measures, and emergency shutdown
procedures.
6. Training and Familiarization: Training requirements for the crew
regarding the safe handling, storage, and discharge of noxious liquid
substances, as well as familiarization with the contents of the P&A
Manual.
The P&A Manual provides essential guidance to ensure that noxious liquid
substances are handled and discharged in a manner that minimizes the risk
of pollution and protects the marine environment and human health.
Compliance with the procedures outlined in the manual is essential for
ships to meet their obligations under MARPOL Annex II regulations.
MARCH-2024
Section: II
1 (a) Explain why it is necessary to have reverse power protection for
alternators intended for operation.
(1) Sketch a reverse power trip.
(ii) Briefly explain the principle on which the operation of this power trip is
based and how tripping is activated.
2 (a) Describe a brush less alternator with a.c. exciter static A.V.R.
(b) State the output voltage characteristics for this type of machine.
3 (a) Which of the following devices will prevent a DC generator from
becoming motorized?
(i) Over current relay
(ii) Motorization trip
(iii) Reverse power relay
(iv) Reverse current relay
(b) Give a detailed explanations as to why other options were not considered
Section: II
4(a) What is a commutator? Discuss its rectifying action in detail.?
(b) Determine the line current taken by a 440V, three-phase, star-connected
motor having an output of 45kW at 0.88(lagging) power factor and an
efficiency of 93 per cent.
5 (a) Describe the effects of changes in speed, rotor current and torque as
load is applied to an induction motor. How does the motor adjust its stator
current with changes in mechanical load?
5 (b) A 20kVA, 2000/220V, single-phase transformer has a primary
resistance of 2.10 and a secondary resistance of 0.0262. The corresponding
leakage reactances are 2.50 and 0.032. Estimate the regulation at full load
under power-factor conditions of
(i) unity
(ii) 0.5 (lagging) and
(iii) 0.5 (Leading).
6 (a) Which of the following three motors has the poorest speed regulation:
shunt motor, series motor or cumulative compound motor? Explain.
(b) An 18.65-kW, 4-pole, 50-Hz, 3-phase induction motor has friction and
windage losses of 2.5 percent of the output. The full-load slip is 4%. Compute
for full load (i) the rotor Cu loss the rotor input (ii) the shaft torque (iii) the
gross electromagnetic torque
Section: III
7 Write reference to gravity lifeboat davits, state the purpose of the
following:
(a) Centrifugal brake
(b) Dead man's handle
(c) Davit limit switch.
8 In engine rooms that are operated under UMS conditions describe with the
aid of sketches how the following are monitored:
(a) The perforation of a high-pressure fuel pipe.
b) Periodical maintenance, checks and tests require to be done to verify the
effectiveness of the above system.
ANS-
(a) Monitoring the perforation of a high-pressure fuel pipe in UMS (Unmanned
Machinery Space) conditions:
In engine rooms operating under UMS conditions, it's crucial to monitor high-
pressure fuel pipes to detect any perforations or leaks promptly. One effective
method is by utilizing pressure sensors along the fuel pipe's length. Here's a sketch
illustrating this monitoring setup:
(a) Monitoring the perforation of a high-pressure fuel pipe in UMS (Unmanned Machinery
Space) conditions:
In engine rooms operating under UMS conditions, it's crucial to monitor high-pressure fuel
pipes to detect any perforations or leaks promptly. One effective method is by utilizing
pressure sensors along the fuel pipe's length. Here's a sketch illustrating this monitoring
setup:
- Pressure sensors (A, B, C) are strategically placed along the high-pressure fuel pipe.
- These sensors continuously monitor the pressure within the fuel pipe.
- If a perforation occurs, there will be a drop in pressure at the sensor nearest to the
leak.
(b) Periodical maintenance, checks, and tests to verify the effectiveness of the above system:
To ensure the effectiveness of the high-pressure fuel pipe monitoring system, regular
maintenance, checks, and tests are necessary. Here's a list of procedures that should be
conducted periodically:
1. Visual Inspections: Regular visual inspections of the high-pressure fuel pipes should
be conducted to look for signs of corrosion, wear, or damage.
2. Pressure Sensor Calibration: Calibration of pressure sensors should be performed at
regular intervals to ensure their accuracy.
3. Functional Tests: Functional tests of the monitoring system should be conducted to
verify that all pressure sensors are operational and transmitting data correctly.
4. Leak Tests: Periodic leak tests should be carried out by introducing controlled leaks
into the system and verifying that the monitoring system detects them accurately.
5. Emergency Response Drills: Regular drills should be conducted to train personnel
on responding to alarms indicating a perforation in the high-pressure fuel pipe.
6. Record Keeping: Comprehensive records should be maintained documenting all
maintenance, checks, tests, and any issues identified and addressed.
By implementing these maintenance procedures, the effectiveness of the high-pressure fuel
pipe monitoring system can be verified and maintained, ensuring the safety and reliability of
the engine room operations under UMS conditions.
9 With reference to MARPOL Annex-IV:
Draw a biological sewage treatment plant and explain the principal of
(a) operation.
(b) Periodical maintenance, checks and tests require to be done to verify the
effectiveness of the above system.
APRIL-2024
1 List the factors that cause deterioration of the frequency response of a
transistor amplifier. Explain how each factor affects the performance of the
amplifier and the portion of the frequency range where it is effective.
2. Sketch and describe the method of speed control of synchronous motors
by variable frequency. State the advantages of this method over the other
methods of speed control.
3. What is soft starting of an Induction motor? Describe with a circuit using
thyristors used for soft starting. Discuss its advantages and dis-advantages.
SECTION II
4. a) Why is it important to maintain high efficiency of operation? And low
values of voltages regulationfor power transformers?
b) A shunt motor supplied at 230 V runs at 900 rpm. When the armature
current is 30 A, the resistance of the armature circuit is 0.4 Ω, calculate the
resistance required in series with the armature circuit to reduce the speed to
500 rpm. Assume that the armature current is 25 Amps.
Type here to search.
5 a) What is back emf? Derive the relation for the back emf and the supplied
voltage in terms of armature resistance.
b) The earth-lamps on a main switchboard comprise two 240V 60W lamps
connected in the usual manner. The potential difference at the busbars is
220V. Damage by sea water occurs
to a distribution cable so that the insulation resistance to the earth is
reduced to 16 ohms and 6 ohms for +ve and -ve cables respectively. Find by
calculation (a) which of the two lamps burns the brighter; and (b) the
additional load on the generators occasioned by the fault. The resistance of
the cables and the ship's structure may be neglected, and that of the lamps
taken as constant at the value corresponding to the 60W rating.
6. (a) Sketch an arrangement showing the principal of a proportional plus
integral (p + 1) control loop.
(b) Compare the series and parallel resonance circuits. Find the frequency at
which the following circuit resonates.
SECTION-III
7. Discuss the following with respect to International Safety Management
(ISM) Code:
a) Emergency preparedness, drills & training.
b) Reporting of near miss, non-conformities, accidents/incidents, and
hazardous occurrences.
c)Risk assessment, Identification of critical equipment, tests, and minimum
spares requirement
8. With reference to a recent ILO notice on the health hazards from asbestos.
a) state where asbestos may be found on board ship.
b) state the health risks from asbestos
c) outline the precautions necessary to minimize exposure to asbestos
during an emergency repair.
9. Petroleum vapours are dangerous substances and when mixed with air
can be ignited. a)
i) sketch an explosimeter or combustion gas indicator which can be used to
check the atmosphere of a tank or pumproom.
ii) describe the explosimeter and its operation iii) state one reason that may
cause the explosimeter to give a false reading
b) for flammable mixtures, explain the meaning of the terms lower and
upper flammable limits.
JUNE - 2024
SECTION-I
1. What are semiconductor devices? What are its advantages over thermionic
devices? With respect to semiconductor devices describe working principle
and application of the following:-
(a) Zener Diode, (b) Transistor, (c) Photocell, (d) Thyristor.
2.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.
3. 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.
Explain how the emergency installation can be periodically tested.
4. With Respect to circuit breakers:
a) Compare the effectiveness of a current limiting circuit breaker with that of
a HRC fuse.
b) A coil having a resistance of 10 ohm and an inductance of 0.15 H is
connected in series with a capacitor across a 100 V, 50 Hz supply. If the
current and the voltage are in phase what will be the value of the current in
the circuit and the voltage drop across the coil?
5. With reference to three phase induction motors:
a) Explain the phenomenon of crawling and cogging in these motors.
5. b) A three-phase induction motor is wound for four poles and is supplied
from a 50 Hz system. Calculate:
i. The synchronous speed
ii. The speed of the rotor when the slip is 4 per cent
iii. The rotor frequency when the speed of the rotor is 600 r/min.
6.a) Describe the working of a single phase full-wave rectifier with a resistive
load. Draw the load voltage and current waveforms.
b) Diode half-wave rectifier supply a resistive load of 1000 from a 100V ac
r.m.s voltage source. The diode is a resistance of 50 during conduction state.
Calculate i) The DC output voltage ii) DC average load current.
SECTION-III
7. What statutory certificates need to be carried by an Indian flagged general
cargo vessel? Name the certificates and state the validity of each of the
certificates.
8. For an ISM certification, explain the key clauses, which are required to be
complied with obtaining Interim DOC, State the responsibility of a ETO with
respect to satisfactory implementation of SMS on board ship.
9.a) Sketch a line diagram of a mechanical low expansion foam fixed
firefighting system suitable for machinery spaces.
b) Describe the operation of the system sketched.
c) Explain how a mixture of foam making compound and sea water are
converted into foam.
JULY - 2024
1.a) what is intrinsic electric safety? Discuss the specific maintenance
protocols,
b ) inspections, and safety measures required to ensure the reliability and
safety of such equipment on board ship.
c) Describe intrinsically safe equipment used on board ship.
2.a) Explain why it is necessary to have reverse power protection for
alternators intended for operation.
b) (i) Sketch a reverse power trip
(ii) Explain briefly the principle on which the operation of this power trip is
based and
how tripping is activated.
3. With reference to U.M.S. operations:
a). State with reasons the essential requirements for unattended machinery
spaces.
b). As ETO, describe how you would respond to the irretrievable failure of
the Machinery space fire alarm system whilst the ship is on voyage.
SECTION II
4.a) Explain the potential hazards if liquid-cooled transformers are used.
b) In a 25 KVA, 3300/233 V, single phase transformer, the iron and full-load
Cu. losses are respectively 350 and 400 watts. Calculate the efficiency at half-
full load, 0.8 power factor.
5.a) List the factors that determine the starting torque of the three-phase
induction motor. How does this torque generally compare with the value of
the rated torque?
b) The low-voltage release of an a.c. motor-starter consists of a solenoid into
which an iron plunger is drawn against a spring. The resistance of the
solenoid is 35 ohm. When connected to a 220 V, 50 Hz, a.c. supply the current
taken is at first 2 A, and when the plunger is drawn into the "full-in" position
the current falls to 0.7 A. Calculate the inductance of the solenoid for both
positions of the plunger, and the maximum value of flux-linkages in weber-
turns for the "full-in" position of the plunger.
6.a) With the aid of delta and star connection diagrams, state the basic
equation from which the delta-star and star-delta conversion equation can
be derived.
b) Three batteries A, B, and C have their negative terminals connected
together. Between the positive terminals of A and B there is a resistor of 0.5
ohm and between B and C there is a resistor of 0.3 ohm.
Specifications of the three batteries are given below:
Battery A 105 V, Internal resistance 0.25 ohm 0.2 ohm
Battery B 100 V, 0.25 ohm
Battery C 95 V.
Determine the current values in the two resistors and the power dissipated
by them.
SECTION-III
7. With reference to an emergency fire pump state -
a). The regulation that influences its location, capacity and power
b) How the power supply to emergency pump is ensured?
c) Why a relief valve is necessary on the deck main?
8.a) Sketch and describe a total flooding CO2 gas system suitable for the
protection of machinery spaces
b) State, with reasons, which valve should be operated first in the system
shown in (A).
9. State how safety is achieved with regard to gas emission in battery rooms
where a large number of lead-acid cells are stored with reference to
a) Provision of lighting
b) Ventilation if a fan is fitted
c) Type of distilled water container for topping up
d) Use of tools and replacement of defective batteries
AUG - 2024
SECTION - I
1.a) Discuss the criteria of the classification of marine high voltage for A-C.
and D.C. Systems. Sketch a Ships high voltage distribution system and explain
its features.
b) Discuss the various methods of testing the insulation of HV system.
Mention the significance of Pi Test, why 3 terminals insulation testers are
used in HV Insulation measurement.
2.a) Describe the circuit breaker for an a.c. generator using a sketch to show
how arcing is Controlled
b) Explain the sequence of events that might occur if the breaker opens on a
short circuit and state the checks you would require following such an event.
c) Give a safe procedure to follow should a main circuit breaker fail to open
under fault Condition.
3.a) Explain how the efficiency and regulation of a transformer can be
assessed by open circuit and short circuit tests?
b) What is meant by equivalent resistance?
SECTION II
4.a) Why is a synchronous motor not self-starting? What are the various
ways in which it can be started?
b) A coil has a resistance of 4 ohms and an inductance of 0.00954 henry.
Calculate the power the coil will absorb and its power factor when it is
connected to a 100-volts 50-cycle supply.
5.a) Describe an accurate method of comparing the capacities of two
condensers.
b) A resistor of 0.525 ohms is connected to the terminals of a battery
consisting of 4 cells, each e.m.f. 1.46 V joined in parallel. The circuit current is
found to be 0.8 A. Find the internal resistance of each cell.
6 a) How does change to frequency affect the operation of the transformer?
What makes this ratio different from the ratio of transformer
b) The coils A and B are connected in series to 50Hz mains. The current is 1A
and the voltage across each coil is measured to be 45V and 70V respectively.
When the coils are connected in a d.c. supply, the current is also 1A, but the
voltages across the coils are now 20V and 40V respectively. Find the
impedance, reactance and resistance of each coil, the total circuit impedance,
the applied a c. voltage and the power factor of the complete circuit.
SECTION-III
7. With reference to "emergency preparedness", discuss
(i) Search and rescue
(ii) Evacuation of critically injured personnel
(iii) Helicopter operation
(iv) Rescue from enclosed spaces
. 8a) Explain the working principle of a hyper mist fire suppression system
on ships. How does this system differ from traditional water-based fire
suppression methods?
b) Discuss the installation, maintenance, and testing requirements for a
hyper mist system on board ships. How does regular upkeep ensure the
system's effectiveness in an emergency?
9.a) Briefly describe the environmental impact of NOx and SOx and allowable
limitations as per Annex VI of MARPOL in emission control areas and outside
emission control areas.
b). Briefly describe methods to control NOx emission
Answer - a) Environmental Impact of NOx and SOx and Allowable
Limitations
SEP– 2024
1. Explain the Principle of Operation of Synchronous Motors with a simple
sketch. Where are synchronous motors used onboard?
2.a) Explain three methods of overcurrent protection for electrical circuit.
b) Explain with aid of diagram, the meaning of the term inverse current time
characteristic.
3. With reference to batteries onboard
a) Distinguish between 'Lead acid cell' and Alkaline Cell
b) Describe how a battery of alkaline cells may be tested for its usefulness,
after a long storage and if found deficient, how it can be remedied?
c)Explain how the ambient temperature is taken into account when
determining the condition of the battery.
SECTION-II
4. With reference to a three-phase shipboard electrical distribution system:
a) Enumerate the advantages of an insulated neutral system;
b) Enumerate the disadvantages of an insulated neutral system;
c) Describe how the Earthed neutral system is Earthed;
d)Compare the use of an insulated neutral system as opposed to the use of an
Earthed neutral system with regard to the risk of electric shock from either
system.
5.a) Which has the greater equivalent resistance; two equal capacitors in
series or in parallel? Explain with reasons?
b)A circuit has a resistance of 3Ω and an Inductance of 0.01H. The voltage
across its ends is 60V and the frequency is 50Hz. Calculate
(a) the impedance
(b) the power factor
(c) the power absorbed.
6a) The capacitor-start induction run motor has a much higher starting
torque than the resistance split-phase motor. Explain
b) A 100 KVA, 2400/240 V, 50 Hz, 1-phase transformer has no-load current
of 0.64 A and a core loss of 700 W. when its high voltage side is energized at
rated voltage and frequency. Calculate the two components of no-load
current. if this transformer supplies a load current of 40 amp at 0.8 lagging
power factor at its low voltage side, determine the primary current and its
power factor. Ignore leakage impedance drop.
SECTION.III
7.a) Discuss the rights and expectations of seafarers in relation to
occupational safety as per Maritime Labor Convention.
b) What are the steps taken to reduce discrimination among seafarers due to
differences in age, gender, language, nationality, and culture.
8. With reference to a lifeboat gravity davit arrangement:
a) Sketch the arrangement showing the lifeboat both in the housed position
and at its maximum point of outboard travel
b). Describe the lowering and raising of lifeboat stating the safety features
and the requirement as per SOLAS 74, with respect to time for hoisting.
9.a) Explain the factors that are considered in the development of critical
equipment and systems onboard ship as per ISM code
b) Give your opinion on the importance of identifying critical equipment and
systems on board ship.