Two resistors of \( 200\,\Omega \) and \( 400\,\Omega \) are connected in series with a battery of \( 100 \, \text{V} \). A bulb rated at \( 200 \, \text{V}, 100 \, \text{W} \) is connected across the \( 400\,\Omega \) resistance. The potential drop across the bulb is _______ \( \text{V} \).