Answer to Question #171644 in Electric Circuits for Pranali Patil

Question

Your oven is wired to 210V and draws 45A of current.

1. What is the power of your oven?
2. Power is usually sold using a price per the unit of kW-hr, which is 1000 Watts used for an hour. If you are baking a cake that takes 37 minutes to bake and the oven operates continuously, how much does it cost if Nova Scotia Power sells 1kW-hr for $0.156?

Answer 1

1)

$$P=VI=210\ V\cdot45\ A=9450\ W=9.45\ kW.$$

2)

$$E=Pt=9.45\ kW\cdot37\ min\cdot\dfrac{1\ h}{60\ min}=5.83\ kWh,$$ $$Cost=5.83\ kWh\cdot 0.156\ \dfrac{\$}{kWh}=\$ 0.91.$$