Electric Power

The video tutorial discusses electric power, starting with its definition as the derivative of potential energy with respect to time. It explores deriving electric power using Ohm's law, resulting in three expressions: current times potential difference, current squared times resistance, and potential difference squared over resistance. The tutorial also clarifies the unit kWh, explaining it as a unit of energy, not power. Finally, it uses a light bulb as an example to demonstrate how power affects brightness in an electric circuit.

What is the relationship between electric power, current, and electric potential difference?

• Power equals current divided by electric potential difference.

• Power equals electric potential difference squared divided by current.

• Power equals current times electric potential difference.

• Power equals current squared divided by electric potential difference.

According to Ohm's law, how can electric power be expressed in terms of current and resistance?

• Power equals current times resistance.

• Power equals resistance divided by current.

• Power equals current squared times resistance.

• Power equals current divided by resistance.

What is the correct interpretation of a kilowatt-hour (kWh)?

• A unit of current.

• A unit of electric potential difference.

• A unit of power.

• A unit of energy.

How many joules are equivalent to one kilowatt-hour?

• 3.6 megajoules

• 3.6 kilojoules

• 360 joules

• 36 megajoules

What happens to the brightness of a light bulb as the power increases?

• The brightness decreases.

• The brightness remains the same.

• The brightness increases.

• The brightness fluctuates.