Sarthaks Test
+1 vote
in Electromagnetic Induction and Alternating Current by (50.1k points)

The current i flowing in a coil varies with time as shown in the figure. The variation of induced emf with time would be-

Please log in or register to answer this question.

2 Answers

+2 votes
by (49.4k points)

Correct answer is :

by (10 points)
But why you chose this answer ?
+1 vote
by (60.6k points)

Induced emf,e = -L\(\frac{di}{dt}\)

For 0 ≤ t ≤  \(\frac{T}{4}\),

i-t graph is a straight line with positive constant slop.

∴ \(\frac{di}{dt}\) = constant

e = -ve and constant, For 0 ≤ t ≤ \(\frac{T}{4}\)

For \(\frac{T}{4}\) ≤ t ≤ \(\frac{T}{2}\)

i is constant ∴ \(\frac{di}{dt}\) = 0

e = 0\(\frac{T}{4}\) ≤ t ≤ \(\frac{T}{2}\)

For \(\frac{T}{2}\)≤ t ≤ \(\frac{3T}{4}\)

i-t graph is a straight line with negative constant slope.

∴  \(\frac{di}{dt}\) = constant

e = +ve and constant For \(\frac{T}{2}\)≤ t ≤ \(\frac{3T}{4}\)

For\(\frac{3T}{4}\)≤ t ≤ T,

i is zero ∴ \(\frac{di}{dt}\) = 0

e = 0 For \(\frac{3T}{4}\)≤ t ≤ T

From this analysis, the variation of induced emf with time as shown in the figure below.

Related questions

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.