RL circuit, current during the transition
A solenoid has an inductance of 53 mH and a resistance of 0.37 `Omega` . If the solenoid is connected to a battery, how long will the current take to reach half its final equilibrium value? (This is a real solenoid because we are considering its small, but nonzero, internal resistance.)

Explanation

To solve the problem, we need to find out how long it takes for the current in an RL circuit to reach half of its final equilibrium value. Here are the steps to arrive at the solution:

### Step 1: Identify the given values
- Inductance (L) = 53 mH = 53 × 10^(-3) H
- Resistance (R) = 0.37 Ω
- Final equilibrium current (I_eq) can be calculated using Ohm's Law.

### Step 2: Calculate the final equilibrium current (I_eq)
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