ABYC MARINE ELECTRICAL CERTIFICATION
EXAM REVIEW 2026 | COMPLETE PRACTICE
1. An electric heater in a 220 Volt circuit raises the temperature of 3 tonnes of oil
by 50 degrees C every 12 hours. The efficiency of the heater is 80% and the
specific heat of oil is 2 kJ/kg oC. Find:
a) the power consumption in kWhours
b) the current taken
c) the resistance of the heater element
Ans: P86 V1
2. a) Show how the electric potential difference (volt) is related to energy (or work)
and quantity of charge.
b) Three capacitors of 2 uF, 3 uF and 5 uF are connected to a 12 volt source,
calculate the total charge of the combinations when they are arranged in :
i) parallel
ii) series
Ans: P18 V2
3. State the definition of the ampere in terms of it's coherence as a basic or
fundamental unit in the International System of Units (SI). Using a sketch indicate
what is meant by "fringing" and by "leakage" in a magnetic circuit. What is the
magnetic flux density at a distance of 5 cm from a very long straight wire carrying
a current of 150 A. Include units in your numerical solution and show that your
answer has the correct units.
note: uo = 4 pi x 10-7
Ans: P34 V2
,4. Explain the terms "fringing" and "leaking" when related to a magnetic circuit. A
magnetic circuit is built up of rectangular metal plates 60 mm wide, having a
combined depth of 80 mm and with the insulating material between the
laminations accounting for 10% of the depth. The circuit has a mean length of 1.8
m with an air gap of length 3 mm and a cross sectional area of 500 mm2. Assume
a leakage factor of 1.1, the relative permeability of iron as 2500 and
the permeability of space as 4 pi x 10-7. Calculate the magnetomotive force
required to produce a flux of 0.006 Wb across the air gap.
Ans: P6 V1
5. A coil of 200 turns is rotated at 1200 RPM between poles of an electromagnet.
Flux density is 0.02 teslas. Axis of rotation is at right angles to the field. Effective
length of the coil is 0.3 meters, mean width is 0.2 meters. Assuming e.m.f.
produced is sinuosoidal, find:
a) maximum value of e.m.f.
b) frequency
Ans: P51 V1
6. A moving coil permanent magnetic instrument has a resistance of 10 ohms and
the flux density in the gap is 0.1 teslas. The coil has 100 turns of wire and is of
mean width 300 mm and axial length is 25 mm. If a p.d. of 50 mV is required for
full scale deflection, calculate the controlling torque exerted by the spring.
Ans: P42 V2
7. The following results of measurements were taken at intervals over a half cycle
of A.C. voltage:
Time 0 0.45 0.95 1.5 2.1 2.5 3.1 3.9 4.5 5.0 (milliseconds)
Volts 0 20 36 40 37.5 33 32 31 20 0
Calculate:
a) the r.m.s. value of the voltage
,b) the frequency of the waveform
Ans: P40 V2
8. A circuit has a resistance of 3 ohms and an inductance of 0.01 henery. The
voltage across this circuit is 60 V and the frequency is 50 Hz. It is a series circuit.
Calculate:
a) impedance
b) line current
c) power factor
d) power absorbed
Ans: P72 V1
9. An iron conductor and an aluminum conductor are connected in parallel to a
supply. The iron conductor is 10% longer and half the diameter of the aluminum
conductor. Given that the ratio of the resistivities of iron to aluminum is 40 : 13
find the ratio of the currents in the two conductors.
10. A wire is 60 meters long and weight of 200 grams. A second wire is 70 feet
long and weighs 6 oz. The specific resistance of the second wire is 10% less than
that of the first, and the material of the first wire is 2% less in weight per cu. inch
than the material of the second wire. Find the ratio of resistance of the second wire
to that of the first.
***imperial units?????
Ans: P24 V1
11. An electric heater consists of 8 elements connected in parallel to a 220 volt
supply and heats up 10 tonnes of oil 35o C in a 24 hour period. If the specific heat
of the oil is 2.17 kJ/kg oC and the efficiency of the heater is 70% find:
a) the current taken
b) the resistances of one of the elements if they are all of the same value.
, Ans: P35 V1
20. Express each of the following voltages in phasor notation and locate them on a
phasor diagram:
V1 = 212.0 sin (wt + 45 deg)
V2 = 141.4 sin (wt - 90 deg)
V3 = 127.3 cos (wt + 30 deg)
V4 = 85.0 cos (wt - 45 deg)
V5 = 141.4 sin (wt + 180 deg)
Ans: P9 V1
12. To find the resistance of a coil, an ammeter and a voltmeter are used. The
ammeter which has a resistance of 0.005 ohm, is connected in series with the coil,
and the voltmeter, which has a resistance of 5000 ohms is connected across the
ends of the coil. When the voltmeter registers 210 volts the ammeter registers 3
amperes. The resistance of the coil was then calculated from the voltmeter reading
divided by the ammeter reading. Calculate the % error in this value.
Ans: P47 V2
13. Given a meter movement that has full scale deflection current of 0.015 A and 5
ohms resistance, calculate the shunt resistor required to use this meter in a 20
ampere circuit
and also the multiplier resistor that would be necessary to use it in a 50 volt circuit.
Ans: P8 V2
14. Two lamps with the following characteristics are to be connected in series
across a 230 volt supply. A lamp is 110 volts and 40 watts whilst the other is 100
volts and 150 watts. Indicate by a sketch and calculation how they can be
connected so that they operate within their characteristics.
EXAM REVIEW 2026 | COMPLETE PRACTICE
1. An electric heater in a 220 Volt circuit raises the temperature of 3 tonnes of oil
by 50 degrees C every 12 hours. The efficiency of the heater is 80% and the
specific heat of oil is 2 kJ/kg oC. Find:
a) the power consumption in kWhours
b) the current taken
c) the resistance of the heater element
Ans: P86 V1
2. a) Show how the electric potential difference (volt) is related to energy (or work)
and quantity of charge.
b) Three capacitors of 2 uF, 3 uF and 5 uF are connected to a 12 volt source,
calculate the total charge of the combinations when they are arranged in :
i) parallel
ii) series
Ans: P18 V2
3. State the definition of the ampere in terms of it's coherence as a basic or
fundamental unit in the International System of Units (SI). Using a sketch indicate
what is meant by "fringing" and by "leakage" in a magnetic circuit. What is the
magnetic flux density at a distance of 5 cm from a very long straight wire carrying
a current of 150 A. Include units in your numerical solution and show that your
answer has the correct units.
note: uo = 4 pi x 10-7
Ans: P34 V2
,4. Explain the terms "fringing" and "leaking" when related to a magnetic circuit. A
magnetic circuit is built up of rectangular metal plates 60 mm wide, having a
combined depth of 80 mm and with the insulating material between the
laminations accounting for 10% of the depth. The circuit has a mean length of 1.8
m with an air gap of length 3 mm and a cross sectional area of 500 mm2. Assume
a leakage factor of 1.1, the relative permeability of iron as 2500 and
the permeability of space as 4 pi x 10-7. Calculate the magnetomotive force
required to produce a flux of 0.006 Wb across the air gap.
Ans: P6 V1
5. A coil of 200 turns is rotated at 1200 RPM between poles of an electromagnet.
Flux density is 0.02 teslas. Axis of rotation is at right angles to the field. Effective
length of the coil is 0.3 meters, mean width is 0.2 meters. Assuming e.m.f.
produced is sinuosoidal, find:
a) maximum value of e.m.f.
b) frequency
Ans: P51 V1
6. A moving coil permanent magnetic instrument has a resistance of 10 ohms and
the flux density in the gap is 0.1 teslas. The coil has 100 turns of wire and is of
mean width 300 mm and axial length is 25 mm. If a p.d. of 50 mV is required for
full scale deflection, calculate the controlling torque exerted by the spring.
Ans: P42 V2
7. The following results of measurements were taken at intervals over a half cycle
of A.C. voltage:
Time 0 0.45 0.95 1.5 2.1 2.5 3.1 3.9 4.5 5.0 (milliseconds)
Volts 0 20 36 40 37.5 33 32 31 20 0
Calculate:
a) the r.m.s. value of the voltage
,b) the frequency of the waveform
Ans: P40 V2
8. A circuit has a resistance of 3 ohms and an inductance of 0.01 henery. The
voltage across this circuit is 60 V and the frequency is 50 Hz. It is a series circuit.
Calculate:
a) impedance
b) line current
c) power factor
d) power absorbed
Ans: P72 V1
9. An iron conductor and an aluminum conductor are connected in parallel to a
supply. The iron conductor is 10% longer and half the diameter of the aluminum
conductor. Given that the ratio of the resistivities of iron to aluminum is 40 : 13
find the ratio of the currents in the two conductors.
10. A wire is 60 meters long and weight of 200 grams. A second wire is 70 feet
long and weighs 6 oz. The specific resistance of the second wire is 10% less than
that of the first, and the material of the first wire is 2% less in weight per cu. inch
than the material of the second wire. Find the ratio of resistance of the second wire
to that of the first.
***imperial units?????
Ans: P24 V1
11. An electric heater consists of 8 elements connected in parallel to a 220 volt
supply and heats up 10 tonnes of oil 35o C in a 24 hour period. If the specific heat
of the oil is 2.17 kJ/kg oC and the efficiency of the heater is 70% find:
a) the current taken
b) the resistances of one of the elements if they are all of the same value.
, Ans: P35 V1
20. Express each of the following voltages in phasor notation and locate them on a
phasor diagram:
V1 = 212.0 sin (wt + 45 deg)
V2 = 141.4 sin (wt - 90 deg)
V3 = 127.3 cos (wt + 30 deg)
V4 = 85.0 cos (wt - 45 deg)
V5 = 141.4 sin (wt + 180 deg)
Ans: P9 V1
12. To find the resistance of a coil, an ammeter and a voltmeter are used. The
ammeter which has a resistance of 0.005 ohm, is connected in series with the coil,
and the voltmeter, which has a resistance of 5000 ohms is connected across the
ends of the coil. When the voltmeter registers 210 volts the ammeter registers 3
amperes. The resistance of the coil was then calculated from the voltmeter reading
divided by the ammeter reading. Calculate the % error in this value.
Ans: P47 V2
13. Given a meter movement that has full scale deflection current of 0.015 A and 5
ohms resistance, calculate the shunt resistor required to use this meter in a 20
ampere circuit
and also the multiplier resistor that would be necessary to use it in a 50 volt circuit.
Ans: P8 V2
14. Two lamps with the following characteristics are to be connected in series
across a 230 volt supply. A lamp is 110 volts and 40 watts whilst the other is 100
volts and 150 watts. Indicate by a sketch and calculation how they can be
connected so that they operate within their characteristics.
