Use app×
Join Bloom Tuition
One on One Online Tuition
JEE MAIN 2025 Foundation Course
NEET 2025 Foundation Course
CLASS 12 FOUNDATION COURSE
CLASS 10 FOUNDATION COURSE
CLASS 9 FOUNDATION COURSE
CLASS 8 FOUNDATION COURSE
0 votes
330 views
in General by (115k points)
closed by
A single-phase transformer has maximum efficiency of 98 %. The core losses are 80 W and the equivalent winding resistance as seen from the primary side is 0.5 Ω. The rated current on the primary side is 25 A. The percentage of the rated input current at which the maximum efficiency occurs is
1. 35.7%
2. 50.6%
3. 80.5%
4. 100%

1 Answer

0 votes
by (113k points)
selected by
 
Best answer
Correct Answer - Option 2 : 50.6%

Concept:

For maximum efficiency to occur in a transformer

Ironlosses = copperlosses

Wi = Wcu

Wi = x2 × WcuFL

\(x = \sqrt {\frac{{{W_i}}}{{{W_{cuFL}}}}} \)

Here,

x = percentage of loading at maximum efficiency

WcuFL = full load copper losses

Calculation:

Given:

Rprimary = 0.5 Ω, Irated = 25 A, Wi = 80 W, ηmax = 98%

WcuFL = I2rated × Rprimary = 252 × 0.5 = 312.5 W

\(x = \sqrt \frac{{80}}{{312.5}}\)

x = 0.505 = 50.5%

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.

Categories

...