Answer:
466.67 s or 7.78 min
Explanation:
Applying,
E = LdI/dt........................Equation 1
Where E = Energized E.m.f in the solenoid, dI = change in current, dt = change in time.
make dt the subject of the equation,
dt = Ldi/E...................... Equation 2
Given: L = 5.6 H, dI = 100-0 = 100 A, E = 1.2 V
Substitute into equation 2
dt = 5.6(100)/1.2
dt = 560/1.2
dt = 466.67 s
dt = (466.67/60) min = 7.78 min
Hence, it takes 466.67 s or 7.78 min for the solenoid to reach its operating current.
