Question

A 3.04 m -long coil containing 225 loops is wound on an iron core (average ?=1850?0) along with a second coil of 115 loops. The loops of each coil have a radius of 2.60 cm . If the current in the first coil drops uniformly from 13.0 A to zero in 99.0 ms .

Answer 1

Ans)

given data is

A long coil length L=3.04m

First coil Number of turns N₁=225

Wrapped around iron core with ?=1850?_o

Second coil number of turns N₂=115

Both have radius R=2.6cm

Current in first coil drops uniformly from 13A to zero

In time t=99ms=99x10^-3s

a)calculate mutual inductance M

M=(?N₁N₂A)/e

=N₁N₂?r²?/L

=[(225x115x3.14x(2.6)²x(1850x4?x10^-7)]/(3.04)

M=4.20x10^-2 H

Calculate the emf induced in the second coil

?₂=-Mxdi/dt

=(4.20x10^-2)(13/99x10^-3)

=5.5V