A copper wire is wound on a wooden frame, whose shape is that of an equilateral triangle. If the linear dimension of each side of the frame is increased by factor of 3, keeping the number of turns of the coil per unit length of the frame the same, then the self inductance of the coil:
decreases by factor of 9
decreases by a factor of
increases by factor of 3
increases by a factor of 27
Self Inductance -
An emf is induced in the coil or the circuit which oppose the change that causes it. Which is also known back emf.
- wherein
length of frame = 3a
No.of turn =0N
Length of frame
No. of turn =
so
We known self-inductance
l=length of winding =d.N
where d=diameter of wire
Continued
putting l-dN in equation (3)
we set
Self-inductance
so self Inductance
So self inductance coil will increase by 27 factor.
decreases by factor of 9
Option 2)decreases by a factor of
Option 3)increases by factor of 3
Option 4)increases by a factor of 27
Study 40% syllabus and score up to 100% marks in JEE