Answer:
The value is  [tex]\Delta t = 4.0 *10^{-7} \ s[/tex]
Explanation:
From the question we are told that
 The current is [tex]\Delta I = 0.100 \ A[/tex]
 The  inductor  is [tex]L = 2.0mH = 2.0*10^{-3} \ H[/tex]
 The voltage induced is  [tex]\epsilon = 500 V[/tex]
Generally the emf induced is mathematically represented as
   [tex]\epsilon = L * \frac{\Delta I }{\Delta t }[/tex]
Here  [tex]\Delta t[/tex] is the time taken Â
=> Â [tex]\Delta t = \frac{L * \Delta I }{\epsilon }[/tex]
=> Â [tex]\Delta t = \frac{2*10^{-3} * 0.100 }{500 }[/tex]
=> Â [tex]\Delta t = 4.0 *10^{-7} \ s[/tex]
