Electric power can be calculated using various formulas. Which of the following formulas is correct? A) P = V/I B) P = V^2/I C) P = VI D) P = I^2/R

Steps to Solve

1. Identify Relevant Formulas

To calculate electric power, we need to understand the relationship between power, voltage, and current. The basic formula for electric power is given by:

$$ P = VI $$

where $P$ is power, $V$ is voltage, and $I$ is current.

2. Consider the Relationship with Resistance

Additionally, Ohm's Law states that:

$$ V = IR $$

where $R$ is resistance. This can help us derive additional formulas associated with power.

3. Substituting for Resistance

We can substitute $V$ from Ohm's Law into the power formula. This gives us:

$$ P = I(IR) = I^2R $$

This shows that power can also be calculated using current and resistance.

4. Using Voltage and Resistance

We can also derive a formula for power in terms of voltage and resistance. By rearranging Ohm's Law, we find:

$$ I = \frac{V}{R} $$

Substituting this back into the power formula $P = VI$, we have:

$$ P = V \left( \frac{V}{R} \right) = \frac{V^2}{R} $$

Now we have a total of three relevant formulas:

• $P = VI$
• $P = I^2 R$
• $P = \frac{V^2}{R}$

5. Choose the Correct Formula

Given the four options provided in the original question, we must match one of the above derived formulas with the options to find the correct formula for calculating electric power.