unit equivalent

Question

Using the equation ε = −L ΔI / Δt, it can be shown that a Henry is equivalent to a

a. VA/s

b. Vs^2/C.

c. VC/s

d. V/A

Answer 1

Just do a dimensional analysis.

volt = henry amp / sec ⇒

henry = volt sec / amp = volt sec / (coul / sec) = volt sec² / coul

Answer (b) is correct.

Answer 2

You mean V = L * ΔI / Δt

put in the units:

volts = L * amps / seconds

rearrange:

L = volts*seconds / amps

If one of the answers involves coulombs, then replace amps with coulombs/sec