All Courses
Explore Courses UPSC Exam UPSC Test Series Free Notes EduRev Infinity Get the App Login Join for Free
Sign in Open App
JEE Exam  >  JEE Questions  >  A transformer is used to reduce the mains sup... Start Learning for Free
SaveJoin the Discussion on the App
A transformer is used to reduce the mains supply of 220 V to 11 V. If the currents in primary and secondary coils are 5 A and 90 A respectively, efficiency of transformer is
  • a)
    90%
  • b)
    75%
  • c)
    40%
  • d)
    60%
Correct answer is option 'A'. Can you explain this answer?
FREE This question is part of
Download PDF Attempt Test
Download PDF Attempt this Test
Verified Answer
A transformer is used to reduce the mains supply of 220 V to 11 V. If ...
HT side Power = Vp(Primary Voltage) x Ip(Primary Current) = 220 x 5 = 1100 W

LT side Power = Vs(Secondary Voltage) x Is(Secondary current) = 11 x 90 = 990 W

Loss = HT side Power -  LT side Power = 1100-990 = 110 W Or Loss(in %) = (Loss/HT side Power) = 110/1100 = 10%

Efficiency = 100-10 = 90%
View all questions of this test
Most Upvoted Answer
A transformer is used to reduce the mains supply of 220 V to 11 V. If ...
Free Test
FREE
Start Free Test
Start Free Test
Community Answer
A transformer is used to reduce the mains supply of 220 V to 11 V. If ...
Given:
Primary voltage (Vp) = 220 V
Secondary voltage (Vs) = 11 V
Primary current (Ip) = 5 A
Secondary current (Is) = 90 A

To find:
Efficiency of the transformer

Explanation:
Efficiency of a transformer is given by the formula:
Efficiency = (Output power / Input power) × 100%

The power in the primary coil (Input power) is given by the formula:
Input power = Vp × Ip

Similarly, the power in the secondary coil (Output power) is given by the formula:
Output power = Vs × Is

Let's calculate the input power and output power:

1. Input power:
Input power = Vp × Ip
Input power = 220 V × 5 A
Input power = 1100 W

2. Output power:
Output power = Vs × Is
Output power = 11 V × 90 A
Output power = 990 W

Now, let's calculate the efficiency of the transformer:

Efficiency = (Output power / Input power) × 100%
Efficiency = (990 W / 1100 W) × 100%
Efficiency ≈ 0.9 × 100%
Efficiency ≈ 90%

Therefore, the efficiency of the transformer is 90%.
< Previous Question Next Question >
Explore Courses for JEE exam

Similar JEE Doubts

A thermal power plant produces electric power of 600 kW at 4000 V, which is to be transported to a place 20 km away from the power plant for consumers usage. It can be transported either directly with a cable of large current carrying capacity or by using a combination of step-up and step-down transformers at the two ends. The drawback of the direct transmission is the large energy dissipation. In the method using transformers, the dissipation is much smaller. In this method , a step-up transformer is used at theplant side so that the current is reduced to a smaller value. At the consumers end, a step-down transformer is used to supply power to the consumers at the specified lower voltage. It is reasonable to assume that the power cable is purely resistive and the transformers are ideal with power factor unity. All the currents and voltages mentioned are rms values.Q.In the method using the transformers, assume that the ratio of the number of turns in the primary to that in the secondary in the step-up transformer is 1 : 10. If the power to the consumers has to be supplied at 200 V, the ratio of the number of turns in the primary to that in the secondary in the stepdown transformer is

ParagraphA thermal power plant produces electric power of 600 kW at 4000 V, which is to be transported to a place 20 km away from the power plant for consumers’ usage. It can be transported either directly with a cable of large current carrying capacity or by using a combination of step-up and step-down transformers at the two ends. The drawback of the direct transmission is the large energy dissipation. In the method using transformers, the dissipation is much smaller. In this method, a step-up transformer is used at the plant side so that the current is reduced to a smaller value. At the consumers’ end, a step-down transformer is used to supply power to the consumers at the specified lower voltage. It is reasonable to assume that the power cable is purely resistive and the transformers are ideal with the power factor unity. All the currents and voltage mentioned are rms values.Q.In the method using the transformers, assume that the ratio of the number of turns in the primary to that inthe secondary in the step-up transformer is 1 : 10. If the power to the consumers has to be supplied at200 V, the ratio of the number of turns in the primary to that in the secondary in the step-down transformeris

Top Courses for JEEView all

Top Courses for JEE

A transformer is used to reduce the mains supply of 220 V to 11 V. If the currents in primary and secondary coils are 5 A and 90 A respectively, efficiency of transformer isa)90%b)75%c)40%d)60%Correct answer is option 'A'. Can you explain this answer?
Question Description
A transformer is used to reduce the mains supply of 220 V to 11 V. If the currents in primary and secondary coils are 5 A and 90 A respectively, efficiency of transformer isa)90%b)75%c)40%d)60%Correct answer is option 'A'. Can you explain this answer? for JEE 2024 is part of JEE preparation. The Question and answers have been prepared according to the JEE exam syllabus. Information about A transformer is used to reduce the mains supply of 220 V to 11 V. If the currents in primary and secondary coils are 5 A and 90 A respectively, efficiency of transformer isa)90%b)75%c)40%d)60%Correct answer is option 'A'. Can you explain this answer? covers all topics & solutions for JEE 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A transformer is used to reduce the mains supply of 220 V to 11 V. If the currents in primary and secondary coils are 5 A and 90 A respectively, efficiency of transformer isa)90%b)75%c)40%d)60%Correct answer is option 'A'. Can you explain this answer?.
Solutions for A transformer is used to reduce the mains supply of 220 V to 11 V. If the currents in primary and secondary coils are 5 A and 90 A respectively, efficiency of transformer isa)90%b)75%c)40%d)60%Correct answer is option 'A'. Can you explain this answer? in English & in Hindi are available as part of our courses for JEE. Download more important topics, notes, lectures and mock test series for JEE Exam by signing up for free.
Here you can find the meaning of A transformer is used to reduce the mains supply of 220 V to 11 V. If the currents in primary and secondary coils are 5 A and 90 A respectively, efficiency of transformer isa)90%b)75%c)40%d)60%Correct answer is option 'A'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of A transformer is used to reduce the mains supply of 220 V to 11 V. If the currents in primary and secondary coils are 5 A and 90 A respectively, efficiency of transformer isa)90%b)75%c)40%d)60%Correct answer is option 'A'. Can you explain this answer?, a detailed solution for A transformer is used to reduce the mains supply of 220 V to 11 V. If the currents in primary and secondary coils are 5 A and 90 A respectively, efficiency of transformer isa)90%b)75%c)40%d)60%Correct answer is option 'A'. Can you explain this answer? has been provided alongside types of A transformer is used to reduce the mains supply of 220 V to 11 V. If the currents in primary and secondary coils are 5 A and 90 A respectively, efficiency of transformer isa)90%b)75%c)40%d)60%Correct answer is option 'A'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice A transformer is used to reduce the mains supply of 220 V to 11 V. If the currents in primary and secondary coils are 5 A and 90 A respectively, efficiency of transformer isa)90%b)75%c)40%d)60%Correct answer is option 'A'. Can you explain this answer? tests, examples and also practice JEE tests.
Explore Courses for JEE exam

Top Courses for JEE

Explore Courses

Suggested Free Tests

Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev
Get App
© EduRev
Education Revolution
Signup to see your scores go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup