A coil of inductance \( 1 \, \text{H} \) and resistance \( 100\Omega \) is connected to a battery of \( 6 \, \text{V} \). Determine approximately:
(a) The time elapsed before the current acquires half of its steady–state value
(b) The energy stored in the magnetic field associated with the coil at an instant \( 15 \, \text{ms} \) after the circuit is switched on (Given \( \ln 2 = 0.693 \), \( e^{-3/2} = 0.25 \))
