<p>A bulb of resistance 10<math xmlns="http://www.w3.org/1998/Math/MathML"><mi>&#937;</mi></math>, connected to an inductor of inductance L, is in series with an a.c. source marked 100V, 50 Hz. If the phase angle between the voltage and current is&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mi>&#960;</mi><mo>/</mo><mn>4</mn></math>&nbsp;radian, calculate the value of L.</p>