Tag: #ukmmarineengineering

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(a) Describe, with the aid of a sketch, the constructional details of a squirrel cage rotor as fitted in an induction motor. (7) (b) Explain why some rotors have a double cage. (3) 10 marks Oct 2024, Jul 2023, Mar 2021 Electric motors Oct 2024 (Q10)

EK Electrical Oct 2024 (Q9)

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With reference to reverse power protection for a.c. generators operating in parallel: (a) Explain why traditional reverse power relays, operating on mechanical principles, have been replaced by electronic digital microprocessor types (2) (b) Describe, with the aid of a sketch, a generator reverse power protection circuit that uses an electronic phase sensitive detector. (8) 10…

EK Electrical Jul 2024 (Q11)

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(a) State FIVE essential electrical services that are able to be operable under fire conditions (5) (b) Explain how electric cables for essential services in part (a) pass through bulkheads whilst maintaining gas tight and water tight integrity (3) (c) State the requirements for the cables which supply electrically driven emergency fire pumps. (2) Electrical…

EK Electrical Jul 2024 (Q10)

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Describe, with the aid of a circuit diagram, a synchro-converter for the variable speed control of a.c. motors (10) Jul 2024 (Q10)

EK Electrical Jul 2024 (Q9)

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With reference to paralleling AC generators (a) Outline the requirement for synchronization (3) (b) Explain how KW power is shared (2) (c) Explain how KVar power is shared (1) (d) State SIX types of damage that may be caused when machines are incorrectly synchronised. (4) Generator & circuit protection Jul 2024 (Q9)

EK Electrical Mar 2024 (Q11)

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With reference to a.c switchboards: (a) State, with reasons, the protective devices that are fitted (5) (b) State why a breaker may fail to open under prolonged low voltage conditions (2) (c) Explain the actions to be taken should a main generator circuit breaker stay connected despite repeated efforts to trip it off the board.…

EK Electrical Mar 2024 (Q10)

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(a) Sketch a cross section through an a.c. induction motor. (5) (b) Describe the construction of the a.c. induction motor sketched in part (a). (5) Mar 2024 (Q10)

EK Electrical Mar 2024 (Q9)

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(a) Explain the term power factor. (2) (b) Explain why it is detrimental to have a low power factor. (2) (c) Explain, with the aid of phasor diagrams, how a synchronous motor may be used to assist in power factor correction (6) Mar 2024 (Q9)

EK Electrical Dec 2023 (Q11)

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With reference to the protection of electrical power circuits: (a) Explain discrimination, describing how it is achieved (5) (b) State, with reasons, the type of fuses used for protection (3) (c) Explain preferential tripping (2) Dec 2023 (Q11)

EK Electrical Dec 2023 (Q10)

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