By which of the following methods the temperature rise of windings and other parts may be determined ? (a) Thermometer method (6) Resistance method (c) Embedded temperature detector method (d) Any of the above

By which of the following methods the temperature rise of windings and other parts
may be determined ?
(a) Thermometer method
(6) Resistance method
(c) Embedded temperature detector method
(d) Any of the above
by

1 Answer

Answer :

(d) Any of the above
by

Related questions

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Last Answer : (e) All of the above

Which of the following methods does not take into account the maximum temperature rise under variable load conditions ? (a) Equivalent power method (b) Equivalent current method (c) Method of average losses (d) Equivalent torque method

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By which of the following methods motor rating for variable load drives can be determined ? (a) Method of average losses (b) Equivalent current method (c) Equivalent torque method (d) Equivalent power method (e) All of the above.

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A practical formula for determining the thickness of insulation between low voltage and high voltage windings is (a) 1 + 0.2 kVmm (6) 2 + 0.5 kVmm (c) 4 + 0.7 kV mm (d) 5 + 0.9 kV mm

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If an insulating material is operated beyond the maximum allowable temperature, its life is (a) drastically increased (b) drastically reduced (c) unaffected (d) none of the above

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In D.C. machines the number of slots per pole usually lies (a) between 2 to 4 (b) between 6 to 8 (c) between 9 to 16 (d) between 20 to 30

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In D.C. machines the width of the duct is usually (a) 4 mm (b) 6 mm (c) 8 mm (d) 10 mm

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The stator of a D.C. machine comprises of (a) main poles (6) interpoles (c) frame (d) all of the above

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A current density of _____ is ilsed for large power transformers with forced circulation of oil or with water cooling coils (a) 1.5 to 2.5 A/mm2 (b) 3.5 to 4.5 A/mm2 (c) 4.0 to 5.0 A/mm2 (d) 5.4 to 6.2 A/mm2

Description : A current density of _____ is ilsed for large power transformers with forced circulation of oil or with water cooling coils (a) 1.5 to 2.5 A/mm2 (b) 3.5 to 4.5 A/mm2 (c) 4.0 to 5.0 A/mm2 (d) 5.4 to 6.2 A/mm2

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Power transformers have rating (a) equal to 50 kVA (6) equal to 100 kVA (c) above 200 kVA (d) none of the above

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Routine maintenance of dry-type transformers should include ____________. A. cleaning the windings, if accessible, with a vacuum cleaner or very low pressure air B. measuring and recording the winding temperature with an accurate mercury thermometer C. periodic cleaning of the winding insulation with an approved solvent D. making sure that the units are close to bulkheads or corners to protect them from damage

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In D.C. machines the usual limit of slot pitch is (a) between 5 to 10 mm (b) between 10 to 15 mm (c) between 15 to 20 mm (d) between 25 to 35 mm

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In D.C. machines, the ____ in field mmf results in increase in size and cost of machines. (a) increase (b) decrease (c) either of the above (d) none of the above

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Last Answer : (a) increase

In D.C. machines, ir order to prevent excessive distortion of field form by the armature reaction, the field mmf must be made (a) equal to that of armature mmf (b) less in comparison with the arma¬ture mmf (c) large in comparison with the arma-ture mmf (d) none of the above

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Last Answer : (c) large in comparison with the arma-ture mmf

D.C. machines designed with a large value of air gap length have (a) worst, ventilation (b) poor ventilation (c) better ventilation (d) none of the above

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Last Answer : (c) better ventilation

In a D.C. machine, the value of peripheral speed should not, normally, exceed (a) 10 m/s (b) 20 m/s (c) 30 m/s (d) 40 m/s

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Last Answer : (c) 30 m/s

In a D.C. machine the number of brush arms is _____ the number of poles. (a) less than (b) equal to (c) greater than (d) none of the above

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Last Answer : (b) equal to