A resistance in a circuit of unknown value...

A resistance in a circuit of unknown value...

Question 1 of 270705eccefa3bacbc34ba4d47f6e

A resistance in a circuit of unknown value is to be tested using the voltmeter/ammeter method. How should the two meters be connected?

Question 1 of 27070

Q

A resistance in a circuit of unknown value is to be tested using the voltmeter/ammeter method. How should the two meters be connected?

🔍 Key Concepts

• Ohm’s Law (V = I × R) and how resistance is calculated from measured voltage and current • How an ammeter is designed to be used in a circuit (low resistance, measures current) • How a voltmeter is designed to be used in a circuit (high resistance, measures potential difference)

💭 Think About

• If you want to find an unknown resistance using V and I, which quantity must flow through the resistor, and which must be measured across it? • Think about what would happen to the circuit if you accidentally put a low-resistance ammeter directly across a power source or component. • Which connection method lets you measure the voltage drop across the resistor without significantly changing the current flowing through it?

✅ Before You Answer

• Be clear on which instrument should be in series with the current path through the resistor. • Be clear on which instrument should be across the two terminals of the resistor. • Eliminate any option where an ammeter would be placed directly across the supply or component, as this could cause a dangerous high current.