A Level Physics Practice Exam

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

Study for the A Level Physics Exam efficiently with engaging quizzes and multiple-choice questions designed to enhance your understanding. Prepare yourself for the challenges of A Level Physics!

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.

When a perfect voltmeter is connected in series, what effect does it have?

Reduces voltage
Increases current flow
Prevents the flow of current
Measures voltage across a load

The correct answer is: Prevents the flow of current

A perfect voltmeter is designed to have infinite resistance, which means it draws no current when connected to a circuit. When a voltmeter is connected in series, its high resistance prevents any current from flowing through the circuit. This results in the voltmeter not affecting the circuit’s behavior, but it also means that the circuit is open, effectively stopping current flow. This characteristic allows it to measure voltage without altering the original circuit parameters. Understanding this principle highlights why a perfect voltmeter, by design, leads to the prevention of current flow when connected in this manner.