An infinitely long wire carries a current of 2 A as shown in the picture. It is
ID: 1287047 • Letter: A
Question
An infinitely long wire carries a current of 2 A as shown in the picture. It is surrounded by a hollow conducting cylinder of inner radius R1 = 2 cm and outer radius R2 = 3 cm that carries a uniform current of 2 A in the opposite direction.
Using Amperes law:
(a) (5 points) Find the magnitude of the magnetic field B at a distance r = 1 cm from the axis of the cylinder.
(b) (6 points) Find the magnitude of the magnetic field B at a distance r = 2.5 cm from the axis of the cylinder.
(c) (5 points) Find the magnitude of the magnetic field B at a distance r = 4 cm from the axis of the cylinder.
Please explain how you solved, thank you !
An infinitely long wire carries a current of 2 A as shown in the picture. It is surrounded by a hollow conducting cylinder of inner radius R1 = 2 cm and outer radius R2 = 3 cm that carries a uniform current of 2 A in the opposite direction. Using Ampere½s law: (a) (5 points) Find the magnitude of the magnetic field B at a distance r = 1 cm from the axis of the cylinder. (b) (6 points) Find the magnitude of the magnetic field B at a distance r = 2.5 cm from the axis of the cylinder. (c) (5 points) Find the magnitude of the magnetic field B at a distance r = 4 cm from the axis of the cylinder.Explanation / Answer
a)B=u0I/(2pi*r)=4pi*10^-7*2/(2pi*0.01)=4*10^-5T
b)Current enclosed in a r=2.5=2-2*(pi*2.5^2-pi*2^2)/(pi*3^2-pi*2^2)=1.1A
B=u0I/(2pi*r)=4pi*10^-7*1.1/(2pi*0.01)=2.2*10^-5T
c)Current enclosed=0
B=0