Equations for Electrical Power Calculation

The video tutorial explains the concept of electrical power and its relation to energy transfer, focusing on three key equations: power from voltage and current (P=V*I), power from current and resistance (P=I^2R), and the relationship between energy and power (E=P*T). It provides practical examples to illustrate how to calculate power and energy transfer in electrical components like lamps and resistors.

Which equation would you use to calculate power if you know the potential difference and current?

• P = I^2 * R

• P = V^2 / R

• P = V * I

• E = P * T

In the first example, what is the power of the lamp if the current is 0.5 amperes and the potential difference is 1.2 volts?

• 1.20 watts

• 0.60 watts

• 2.40 watts

• 0.50 watts

What is the power of a 20 ohm resistor when the current through it is 0.5 amperes?

• 10.0 watts

• 5.0 watts

• 20.0 watts

• 2.5 watts

Which equation is used to calculate the energy transferred by a resistor over time?

• E = P / T

• E = V^2 / R * T

• E = I^2 * R * T

• E = V * I * T

How much energy is transferred by a 5 ohm resistor in 5 minutes with a current of 0.1 amperes?

• 25 joules

• 20 joules

• 15 joules

• 10 joules