Question

1. With a 1200 W toaster, how much electrical energy is needed to make a slice of toast that has a cooking time of 1 minute? At 11 cents/(kW hr), how much does this cost?

2. A wire is drawn through a die, stretching it to four times its original length. By what factor does its resistance increase?

3. A North American tourist takes his 25.0 W, 120 VAC razor to Europe, finds a special adapter, and plugs it into 240 VAC. Assuming constant resistance, what power does the razor consume as it is burning up?

Answer 1