Resistors in Series and Parallel Circuits Experiment - GCSE Physics Required Practical

Summary

This educational video demonstrates how to measure the resistance of resistors in series and parallel circuits. The experiment uses identical resistors, two cells for power, an ammeter, and a voltmeter. It begins by testing a single resistor, recording current and voltage to calculate resistance. Then, it compares resistance when resistors are connected in series and parallel, showing how total resistance changes with different configurations.

Takeaways

• 🔬 The experiment aims to measure the resistance of resistors in series and parallel circuits.
• 🔌 Identical resistors are used, with their values concealed for discovery during the experiment.
• 🔋 A simple circuit is set up using two cells with a maximum voltage of four volts.
• 📏 An ammeter is used to check the current flow and ensure the circuit components are functioning.
• 🔌 The first resistor is connected, and the ammeter reads a current of 0.26 or 0.27 amps.
• 🔌 A voltmeter is connected in parallel to the resistor to measure the voltage, which reads 2.68 volts.
• 🧮 With current and voltage known, the resistance of the first resistor is calculated using Ohm's Law (V=IR).
• 🔄 The process is repeated with the second identical resistor to verify consistency.
• 🔗 When resistors are connected in series, the total resistance increases, as measured by the ammeter and voltmeter.
• 🔄 In parallel, the resistors combine to decrease the total resistance, resulting in a higher current and lower voltage across each resistor.
• 📊 The experiment concludes with measurements for current and voltage in both series and parallel configurations, allowing for the calculation of total resistance in each case.

Q & A

What is the purpose of the experiment described in the transcript?

The purpose of the experiment is to measure the resistance of resistors both in series and in parallel configurations.

What is the maximum voltage the circuit can handle according to the transcript?

The maximum voltage the circuit can handle is four volts.

How many cells are used in the circuit to achieve the maximum voltage?

Two cells are used in the circuit to achieve the maximum voltage of four volts.

What instruments are used in the experiment to measure current and voltage?

An ammeter is used to measure current, and a voltmeter is used to measure voltage.

What is the initial current reading when one resistor is connected to the circuit?

The initial current reading is 0.26 or 0.27 amps when one resistor is connected to the circuit.

What is the voltage reading when the voltmeter is connected in parallel to the resistor?

The voltage reading is 2.68 volts when the voltmeter is connected in parallel to the resistor.

How does the resistance of a resistor get calculated in the experiment?

The resistance of a resistor is calculated using Ohm's Law, which is Voltage = Current × Resistance.

What happens to the current when two identical resistors are connected in series?

The current decreases when two identical resistors are connected in series due to the increased total resistance.

What is the expected change in current when resistors are connected in parallel?

The current is expected to increase when resistors are connected in parallel because the total resistance decreases.

How does the experimenter ensure that the wires are connected correctly when changing from series to parallel?

The experimenter ensures that the wires are connected correctly by carefully observing the connections and removing the voltmeter before making changes.

What is the final current reading when the resistors are connected in parallel?

The final current reading is between 0.47 and 0.48 amps when the resistors are connected in parallel.