Topic Assessment 3 Transformer Operation (60 min)_ Attempt review.pdf

Dashboard / My courses / EL25 - Test and connect transformers / Topic Assessments / Topic Assessment 3 Transformer Operation (60 min) Started on Sunday, 4 August 2024, 11:17 AM State Finished Completed on Sunday, 4 August 2024, 11:24 AM...

Dashboard / My courses / EL25 - Test and connect transformers / Topic Assessments / Topic Assessment 3 Transformer Operation (60 min) Started on Sunday, 4 August 2024, 11:17 AM State Finished Completed on Sunday, 4 August 2024, 11:24 AM Time taken 7 mins 29 secs Marks 8.00/8.00 Grade 100.00 out of 100.00 Feedback Congratulations you have achieved 100%. Good luck with your continued studies. Question 1 Correct Mark 1.00 out of 1.00 Topic Assessment 3 Transformer Operation Question 1 Review the statement/s carefully and indicate True or False. Statement True/False Mutual inductance is the induction of a voltage in one coil in response to a change in current in the other coil True  Your answer is correct. Question 2 Correct Mark 1.00 out of 1.00 Topic Assessment 3 Transformer Operation Question 2 What is the value of self-induced voltage (V1') in the primary winding of a transformer Select one: The same as the applied voltage 180o out of phase with the applied current Slightly more than the applied voltage Slightly less than the applied voltage Your answer is correct. Question 3 Complete Not graded Topic Assessment 3 Transformer Operation Question 3 Zero marks allocated. Question moved to Topic Assessment 5. No need to answer this question. To calculate the voltage regulation of a transformer, which formula is commonly applied? Select one: VREG = (VFL+VNL) / VFL x 100 VREG= (VFL-VNL) / VNL x 100 VREG= (VNL-VFL) / VFL x 100 VREG= (VFLxVNL) / VFL x 100 Your answer is correct. Question 4 Correct Mark 1.00 out of 1.00 Topic Assessment 3 Transformer Operation Question 4 To calculate the current flow in the primary winding of a single-phase transformer, which formula is commonly applied? Select one: N1/N2 = V2/V1 = I2/I1 N1/N2 = V1/V2 = I2/I1 N1/N2 = V1/V2 = I1/I2 N2/N1 = V1/V2 = I1/I2 Your answer is correct. Question 5 Correct Mark 1.00 out of 1.00 Topic Assessment 3 Transformer Operation Question 5 Calculate the secondary voltage when: a 230V 50HZ supply is connected across the primary winding with 1000 turns and, a resistive load of 100 ohms is connected across the terminals of the secondary winding with 500 turns Select one: 240V 135V 115V 460V Your answer is correct. Question 6 Correct Mark 1.00 out of 1.00 Topic Assessment 3 Transformer Operation Question 6 Review the statement/s carefully and indicate True or False. Statement True/False This is a phasor diagram of a transformer with no load indicating voltage with an open arrow head and current with a solid arrow head True  Your answer is correct. Question 7 Correct Mark 1.00 out of 1.00 Topic Assessment 3 Transformer Operation Question 7 Review the statement/s carefully and indicate True or False. Statement True/False This is a phasor diagram where current lags the voltage True  Your answer is correct. Question 8 Correct Mark 1.00 out of 1.00 Topic Assessment 3 Transformer Operation Question 8 Review the statement/s carefully and indicate True or False. Statement True/False The primary mmf is the only mmf producing the peak value magnetic flux. Power transformers can saturate when voltage to frequency ratio for the particular transformer design is True violated. The transformer is said to be saturated or overexcited when its core can no longer carry flux that is  being generated Your answer is correct. Question 9 Correct Mark 1.00 out of 1.00 Topic Assessment 3 Transformer Operation Question 9 What must every electrical worker who is listed on the access permit as being allowed to be in close proximity to high-voltage apparatus do? Select one: Not communicate with others on site Wear PPE as a control measure against electric shock and arc flash Ignore site signage Work through their lunch break Your answer is correct. Question 10 Complete Not graded Topic Assessment 3 Transformer Operation Question 10 Zero marks allocated. Question moved to Topic Assessment 2. No need to answer this question. A load connected to a three-phase, three-wire 11 000/415 V line-to-line potential requires measurement. It is estimated to be 3000 kVA. From the following, select a suitable current and potential transformer. CT to provide metering current of 0-5A PT to provide metering voltage of 110V Select one: Current transformer with 200:5 ratio and potential transformer with 100:1 ratio Current transformer with 50:5 ratio and potential transformer with 50:1 ratio Current transformer with 50:5 ratio and potential transformer with 100:1 ratio Current transformer with 200:5 ratio and potential transformer with 40:1 ratio Your answer is incorrect. Question 11 Complete Not graded Topic Assessment 3 Transformer Operation Question 11 Zero marks allocated. Question moved to Topic Assessment 2. No need to answer this question. A 1000kVA load is supplied from a three-phase four-wire 11 000 V line. From the following, select a suitable current and potential instrument transformer. CT to provide metering current of 0-5A PT to provide a metering voltage of 110V Select one: Potential transformer with 80:1 ratio and potential transformer with 50:1 ratio Current transformer with 75:5 ratio and potential transformer with 100:1 ratio Current transformer with 75:5 ratio and potential transformer with 80:1 ratio Current transformer with 100:5 ratio and potential transformer with 80:1 ratio Your answer is correct. ◄ Topic Assessment 2 Auto-transformers and Instrument Transformers (60 min) Jump to... Topic Assessment 4 Transformer Losses, Efficiency and Cooling (60 min) ►