The temperature rise of transformer is directly proportional to: Real power Apparent power Reactive power None of these Correct answer: 2. Apparent power The temperature rose of transformer is directly proportional to the apparent power.
Category: Electrical Machines
Potential Transformer MCQ Questions with Answers
A Potential transformer or PT is a type of special-purpose transformer that is designed to sample high voltage and provide a low secondary voltage that is directly proportional to it. Given below are most important basic MCQs on Potential transformers. Secondary winding rating of Potential Transformer Usually, Potential transformers have a secondary winding rating of: […]
Current Transformer MCQ Questions with Answers
A current transformer is a type of instrumentation transformer that steps down current in power systems to safe levels that can be processed via relays and measurement devices/equipment. Current transformers can be found in generation stations and switching stations. Given below are the most important Current Transformer MCQ Questions Secondary winding rating of Current Transformer […]
The voltage regulation of synchronous generator operating at unity power factor is
The voltage regulation of synchronous generator operating at unity power factor is: Small Negative Zero Small Positive None of these Correct answer: 3. Small positive Explanation: Voltage regulation is mathematically defined as: VR = (Vnl – Vfl)/ Vfl For unity power factor loads, the full load voltage is smaller (but nearly closer to full load voltage) […]
The voltage regulation of synchronous generator operating at a leading power factor is
The voltage regulation of synchronous generator operating at a leading power factor is: Negative Positive Zero None of these Correct answer: 1. Negative Explanation: The basic formula for voltage regulation is: VR = (Vnl – Vfl)/ Vfl For leading power factor the full load voltage (Vfl) is higher than the no-load voltage (Vnl) and thus the […]
The voltage regulation of synchronous generator operating at a lagging power factor is
The voltage regulation of synchronous generator operating at a lagging power factor is: Negative Zero Positive None of these Correct answer: 3. Positive The synchronous generator operating at the lagging power factor has large positive voltage regulation. Voltage regulation is mathematically defined as: VR = (Vnl – Vfl)/ Vfl For lagging power factor the no-load voltage […]
In case there are burrs on the edges of the laminations of the transformer, which one of the following is likely to result – Transformer MCQ#48
In case there are burrs on the edges of the laminations of the transformer, which one of the following is likely to result: Vibrations Greater eddy current losses More noise Greater hysteresis losses Correct answer: 2. Greater eddy current losses
Which of the following single-phase motor has comparatively poor starting torque – Induction Motor MCQ#81
Which of the following single-phase motor has comparatively poor starting torque: Universal motor Repulsion motor Capacitor motor All single phase motors have zero starting torque Correct answer: 3. Capacitor motor
The Buchholz relay can be installed on – Transformer MCQ#80
The Buchholz relay can be installed on: Auto-transformers Oil cooled transformers Air-cooled transformers Welding transformers Correct answer: 2. Oil cooled transformers
Sumpner’s test is conducted on transformers to determine – Transformer MCQ#79
Sumpner’s test is conducted on transformers to determine: Temperature Stray losses All-day efficiency None of the above Correct answer: 1. Temperature