Certified Fire Investigator Practice Exam

What formula represents Ohm's Law?

1. V = I + R

2. E = I * R

3. E = I / R

4. E = I (Voltage) R (Resistance)

The correct answer is: E = I * R

Ohm's Law is a fundamental principle in electrical engineering that describes the relationship between voltage, current, and resistance in an electrical circuit. The correct representation of Ohm's Law is expressed in the form of the equation \( E = I * R \), where \( E \) (or \( V \)) stands for voltage, \( I \) represents current, and \( R \) signifies resistance. This formula indicates that voltage is the product of current flowing through a conductor and the resistance of that conductor. Thus, when you increase the current or the resistance, the voltage increases proportionately. Understanding this relationship is critical in circuits as it helps engineers and technicians calculate necessary parameters for designing and trouble-shooting electrical systems safely and effectively. The other choices do not accurately reflect the relationship dictated by Ohm’s Law, which is bidirectional and involves multiplication rather than addition or division. Recognizing and applying this accurate form of Ohm's Law is essential for anyone working with electrical systems.