The charging curve is governed by the L/R inductive time constant.
Current will reach its maximum Amperage after 5 time constants (customary figure). It will reach 63% of maximum after 1 time constant.
In your example... Maximum Amperage is equal to 24 V divided by 7 ohms (3.43 A). Voltage is applied for 1/90,000 of a second. (11 uSec)
In 11 uSec, current will reach a proportionate fraction of 3.43A, as 11 uSec is in ratio to the inductive time constant. Although the curve is not straight, we pretend it is for the sake of ease.