Energy And Voltage In Circuits
Overview
Every circuit question on the Edexcel papers comes down to understanding how current, voltage and resistance relate to each other. Whether components are wired in series or parallel changes the rules, and knowing those rules lets you solve any circuit problem.
In this lesson you will learn about series and parallel circuits, V = IR, Q = It, I-V characteristics of components, LDRs, thermistors, current conservation, voltage sharing, and E = QV.
Objectives
- Explain why a series or parallel circuit is more appropriate for particular applications
- Understand how the current in a series circuit depends on the applied voltage and the number and nature of other components
- Describe how current varies with voltage in wires, resistors, metal filament lamps and diodes
- Describe the qualitative effect of changing resistance on the current in a circuit
- Describe the qualitative variation of resistance of LDRs with illumination and of thermistors with temperature
- Know that lamps and LEDs can be used to indicate the presence of a current in a circuit
- Know and use the relationship: voltage = current x resistance
- Know that current is the rate of flow of charge
- Know and use the relationship: charge = current x time
- Know that electric current in solid metallic conductors is a flow of negatively charged electrons
- Understand why current is conserved at a junction in a circuit
- Know that the voltage across two components connected in parallel is the same
- Calculate the currents, voltages and resistances of two resistive components connected in a series circuit
- Know that voltage is the energy transferred per unit charge passed and the volt is a joule per coulomb
- Know and use the relationship: energy transferred = charge x voltage
Lesson Note
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Lesson Evaluation
Congratulations on completing the lesson on Energy And Voltage In Circuits. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.
You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.
Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.
- In a series circuit, current is: A) Different through each component B) The same through all components C) Zero D) Shared equally between components Answer: B
- V = IR. If V = 12 V and R = 4 ohms, I is: A) 48 A B) 3 A C) 16 A D) 0.33 A Answer: B
- In parallel, the voltage across each branch is: A) Shared equally B) Zero C) The same as the supply D) Doubled Answer: C
- An LDR in darkness has: A) Low resistance B) High resistance C) Zero resistance D) Infinite conductance Answer: B
- 1 volt equals: A) 1 joule per ampere B) 1 joule per coulomb C) 1 coulomb per second D) 1 watt per ampere Answer: B
Available on the Green Bridge App
Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.
Available on the Green Bridge App
Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.
Practice Mock Questions
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