You buy a 75 W lightbulb in Europe, where electricity is delivered to homes at 240 V (meaning that the lightbulb is designed to deliver 75 W at 240 V). If you use this European lightbulb in the United States at 120 V (assuming its resistance does not change), how bright will it be relative to a U. S. lightbulb designed to deliver 75 W at 120 V. Hint: Assume that brightness is roughly proportional to power consumed.