00:01
Hello, in part a of this question we have to find the energy stored in the magnetic field of the coil.
00:06
First, the inductance of the coil can be expressed as l is equal to mu zero n square a divided by 2 pi r.
00:16
Here mu zero is the probability of free space, n is the number of turns of the coil, a is the area of cross -section of the coil and r is the radius of the coil.
00:26
Now r can be expressed as equal to d divided by 2, d is the diameter of the coil.
00:32
It equals 40 cm divided by 2 equals 20 cm which can be written as equal to 20 into 10 raised 2 meters.
00:44
Now let's substitute all the non -values in this equation.
00:48
So it equals musura is 4 pi into 10 raise 2 minus 7 henry per meter into n is 1 ,000 square into a is given to be equal to 20 cm square, it can be written as equal to 20 into 10 raised to minus 4 meter square.
01:08
So we can write 20 into 10 raised to minus 4 meter square divided by 2 pi into r is obtained as 20 into 10 raised to minus 2 meter.
01:21
So it equals 0 .002 henry.
01:27
Now the energy stored in an inductor can be expressed as.
01:31
E is equal to 1x2 l .i...