The current in a simple electrical circuit is inversely proportional to the resistance. If the current is 40 amperes​ (an ampere is a unit for measuring​ current) when the resistance is 5 ​ohms, find the current when the resistance is 7.2 ohms.

To solve this problem, we will use the concept of inverse proportionality, which means that if one quantity increases, the other decreases in such a way that their product remains constant. 

Mathematically, if the current \( I \) is inversely proportional to the resistance \( R \), then:

\[
I \propto \frac{1}{R}
\]

This relationship can be expressed as:

\[
I \times R = k
\]

where \( k \) is a constant.

Given:
- \( I = 40 \) amperes when \( R = 5 \) ohms.

First, we calculate the constant \( k \):

\[
k = I \times R = 40 \times 5 = 200
\]

Now, we need to find the current \( I \) when the resistance \( R = 7.2 \) ohms. Using the same equation:

\[
I \times 7.2 = 200
\]

Solve for \( I \):

\[
I = \frac{200}{7.2} \approx 27.78 \text{ amperes}
\]

So, the current is approximately \( 27.78 \) amperes when the resistance is \( 7.2 \) ohms.

Would you like more details or have any questions?

Here are 5 related questions for further practice:

1. What would the current be if the resistance increased to 10 ohms?
2. How does the current change if the resistance is halved?
3. What is the relationship between current and voltage in an electrical circuit?
4. How would you calculate the resistance if the current and constant \( k \) are known?
5. Can you explain what happens to the current if resistance approaches zero?

**Tip:** In circuits, always remember Ohm's Law, which relates voltage, current, and resistance directly: \( V = I \times R \).

The current in a simple electrical circuit is inversely proportional to the resistance. If the current is 40 amperes when the resistance is 5 ohms, find the current when the resistance is 7.2 ohms.

Learn how to solve an electrical circuit problem where the current is inversely proportional to the resistance. This example shows step-by-step calculations using the inverse proportionality concept and formulas, suitable for students in Grades 8-10.

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