Advertisements
Advertisements
Question
The magnetic flux through a coil having 100 turns decreases from 5 milli weber to zero in 5 second. Calculate the e.m.f. induced in the coil.
Advertisements
Solution
Given that:
Decrease in the flux = 0.005 - 0 = 0.005 weber,
Number of tuns = 100 turns and
Time = 5 second
e.m.f. induced e = N × Rate of increase of magnetic flux
`= 100 xx 0.005/5`
∴ e.m.f. induced e = 0.1 V
= 100 mV
APPEARS IN
RELATED QUESTIONS
Name the material used for making the armature of an electric bell. Give a reason for your answer.
principle of an electric motor ?
Name the type of transformer shown in fig . What changes will you observe regarding the brightness of the lamp, if
(a) The no. of turns in the secondary is doubled?
(b) The part X of the transformer is removed?
( c) The core of the transformer is made out of copper?
(d ) The A.C. supply is replaced by D.C.?

Fill in the blanks by writing (i) Only soft iron, (ii) Only steel, (iii) Both soft-iron and steel for the material of core and/or magnet.
Electric bell ______.
State the two properties of the magnetic lines of force around a circular coil.
How does a magnetic field set up by a solenoid change when a soft iron core is inserted inside solenoid?
Why is soft iron generally used as the core of the electromagnet?
State the condition when an electric charge can give rise to a magnetic field.
What is a permanent magnet? Give one use of it.
State the position of armature coil relative to the direction of magnetic field, in a D. C. motor when the deflecting couple acting an the coil is maximum.
