The magnetic field in a solenoid is B mu0NId A circular wir

The magnetic field in a solenoid is B = (mu_0NI)/d. A circular wire of radius 13 cm is concentric with a solenoid of radius 1 cm and length d = 4 meter, containing 9000 turns. The current increases at a rate of 43 A/s. What is the emf in the wire? 0.000153 V What is the non - Coulomb electric field in the wire? V/m

Solution

Here ,

r = 0.13 m

radius of solenoid , r1 = 0.01 m

L = 4 m

N = 9000

di/dt = 43 A/s

Now , for the emf in the coil

emf in the wire = u0 * N * di/dt/L * pi * r1^2

emf in the wire = 4pi *10^-7 * 9000/4 * 43 * pi * 0.01^2

emf in the wire = 3.82 *10^-5 V

b)

Now ,for the electric field E

E * 2pi * r = V

E * 2pi * 0.13 = 3.82 *10^-5

E = 4.68 *10^-5 V/m

the electric field is 4.68 *10^-5 V/m