To find the power generated in the circuit, we need to combine Ohm's Law with the power formula. Here is the step-by-step solution:
1. Identify the given values:
* Voltage ($V$) = $12\text{ V}$
* Resistance ($R$) = $40\text{ }\Omega$
2. Choose the correct formula:
The basic formula for power is $P = V \times I$. However, we don't know the current ($I$) yet. We can use Ohm's Law ($V = I \times R$) to substitute for $I$.
From Ohm's Law, we know that $I = \frac{V}{R}$.
If we plug this into the power equation, we get a new formula that uses only Voltage and Resistance:
$$P = \frac{V^2}{R}$$
*(Alternatively, you can calculate the current first: $I = \frac{12}{40} = 0.3\text{ A}$, and then multiply by voltage: $P = 12 \times 0.3$)*
3. Perform the calculation:
Using the formula $P = \frac{V^2}{R}$:
* First, square the voltage: $12^2 = 144$
* Next, divide by the resistance: $\frac{144}{40}$
$$144 \div 40 = 3.6$$
So, the power is $3.6\text{ Watts}$.
Final Answer:
(B) 3.6W
Parent Tip: Review the logic above to help your child master the concept of ohms law practice worksheet.
