Case Study Question for Class 12 Physics Chapter 6 Electromagnetic Induction
Question 1:
Read the para given below and answer the questions that follow:
Self Induction. When a current I flows through a coil, flux linked with it is φ = LI, where L is a constant known as self inductance of the coil.
Any charge in current sets up an induced emf in the coil. Thus, self inductance of a coil is the induced emf set up in it when the current passing through it changes at the unit rate. It is a measure of the opposition to the growth or the decay of current flowing through the coil. Also, value of self inductance depends on the number of turns in the solenoid, its area of cross-section and the permeability of its core material.
(i) The inductance in a coil plays the same role as
(a) inertia in mechanics
(b) energy in mechanics
(c) momentum in mechanics
(d) force in mechanics
(ii) A current of 2.5 A flows through a coil of inductance 5 H. The magnetic flux linked with the coil is
(a) 0.5 Wb
(b) 12.5 Wb
(c) zero
(d) 2 Wb
The inductance L of a solenoid depends upon its radius R as
(a) L ∝ R
(b) L ∝ 1/R
(c) L ∝ R2
(d) L ∝ R3
(iv) The unit of self-inductance is
(a) Weber ampere
(b) Weber-1 ampere
(c) Ohm second
(d) Farad
(v) The induced emf in a coil of 10 henry inductance in which current varies from 9 A to 4 A in 0.2
second is
(a) 200 V
(b) 250 V
(c) 300 V
(d) 350 V
Answer
Answer:(i) a
(ii) b
(iii) c
(iv) c
(v) b
