20. Given the formula \( E=I R \) what is the formula for \( R \) ? A. \( R=I \div E \) B. \( R=E \div I \) C. \( R=E I \) D. \( R=I E \)

To find the formula for \( R \) from \( E = I R \), you can rearrange the equation. By dividing both sides by \( I \), you get \( R = E \div I \). So, the correct answer is B. \( R=E \div I \). Now, let's throw in some extra fun facts related to electrical equations! Ever wondered how Ohm's Law is key to electrical engineering? It defines the relationship between voltage (E), current (I), and resistance (R) and is foundational for designing circuits, ensuring everything functions safely and efficiently. And did you know that in practical applications, resistance can change due to factors like temperature? Materials like metals typically have higher resistance when warmed up, leading to potential challenges in circuit design. Understanding these nuances helps engineers avoid common pitfalls like overheating components!