ARRL Technician Practice Exam

Disable ads (and more) with a membership for a one time $2.99 payment

Prepare for the ARRL Technician Exam. Study with flashcards and multiple choice questions, each question has hints and explanations. Get ready for your exam!

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

Practice this question and more.

Which formula is used to calculate current in a circuit?

Voltage (E) divided by resistance (R)
Resistance (R) divided by voltage (E)
Voltage (E) multiplied by current (I)
Current (I) multiplied by resistance (R)

The correct answer is: Voltage (E) divided by resistance (R)

The formula for calculating current in a circuit is derived from Ohm's Law, which states that the current (I) flowing through a conductor between two points is directly proportional to the voltage (E) across the two points and inversely proportional to the resistance (R) of the conductor. This relationship is expressed mathematically as: I = E / R In this formula, current (I) is the result of dividing the voltage (E) by the resistance (R). This means that for a given voltage, if the resistance increases, the current will decrease, and conversely, if the resistance decreases, the current will increase. This concept is fundamental in electronics and electrical engineering as it describes how voltage, current, and resistance interact within a circuit. Understanding this relationship is crucial for technicians when troubleshooting circuits or designing electrical systems. The other options do not represent valid relationships per Ohm's Law and therefore do not yield the correct expression for calculating current.