Question

A cell is connected across two points on a uniform circular conductor. prove that the magnetic field at the centre


will be zero.

Answer 1

As conductor is connected with the cell , the potential difference across two paths (two possible paths i.e. one upside and one downside path) is same.

V1 = V2

I1R1=I2R2

I1dl1=I2dl2 (as resistivity and area of cross section same )

 

Now, 

field, due to one path, is opposite due to another part. So magnetic field at the center is

 

[sin 90 = 1 , i1dl1  = i2dl2]

= 0 (proved)

 As conductor is connected with the cell , the potential difference across two paths (two possible paths i.e. one upside and one downside path) is same.

V1 = V2

I1R1=I2R2

I1dl1=I2dl2 (as resistivity and area of cross section same )

 

Now, 

field, due to one path, is opposite due to another part. So magnetic field at the center is

 

[sin 90 = 1 , i1dl1  = i2dl2]

= 0 (proved)

 

Answer 2

What that question it no no