Answer:
magnetic field = 8.67 ×[tex]10^{-7}[/tex] T
dE/dt = 2.25×[tex]10^{-12}[/tex] V/ms
Explanation:
given data
diameter = 28 cm
current = 20 A/m²
r= 69 mm = 69 ×[tex]10^{-3}[/tex] m
to find out
magnetic field and dE/dt
solution
we will apply here magnetic field formula that is
magnetic field = μ I / 2πr .............1
put here all value
magnetic field = μ (Jπr²) / 2πr
magnetic field = 4π ×[tex]10^{-7}[/tex] (20) ( 69 ×[tex]10^{-3}[/tex]) / 2
magnetic field = 8.67 ×[tex]10^{-7}[/tex] T
and dE/dt is calculated by current that is
current I = ∈A dE/dt
so
dE/dt = I / ∈A ....................2
that is dE/dt = J / ∈
dE/dt = 20 / 8.85 ×[tex]10^{-12}[/tex]
dE/dt = 2.25×[tex]10^{-12}[/tex] V/ms