Current And Voltage In Circuits
Overview
Every electronic device you use relies on electric current flowing through a circuit. Understanding how current and voltage behave in different circuit arrangements is essential for predicting how components work together.
In this lesson you will learn what current and voltage really measure, how to use Ohm's law to calculate resistance, and how current and voltage distribute themselves in series circuits. You will also explore I-V characteristics for resistors, filament lamps and diodes - a favourite topic on Edexcel papers.
Objectives
- 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 and metal filament lamps, and how to investigate this experimentally
- Describe the qualitative effect of changing resistance on the current in a circuit
- Know that lamps and LEDs can be used to indicate the presence of a current in a circuit
- Know and use the relationship between voltage, current and resistance: V = I x R
- Know that current is the rate of flow of charge
- Know that electric current in solid metallic conductors is a flow of negatively charged electrons
- Calculate the currents, voltages and resistances of two resistive components connected in a series circuit
Mind map
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Flashcards
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Lesson Note
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Lesson Evaluation
Congratulations on completing the lesson on Current 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.
- Electric current in a metal wire is a flow of: A) Protons B) Neutrons C) Electrons D) Ions Answer: C
- An ammeter should be connected: A) In parallel with the component B) In series with the component C) Across the battery D) It does not matter Answer: B
- Two resistors of 6 ohms and 4 ohms are connected in series. What is the total resistance? A) 2.4 ohms B) 10 ohms C) 24 ohms D) 1.5 ohms Answer: B
- The I-V graph for an ohmic conductor is: A) A curve through the origin B) A straight line through the origin C) A horizontal line D) A line that starts at 0.7 V Answer: B
- In a series circuit, the current: A) Is largest near the battery B) Splits between components C) Is the same at all points D) Depends on the voltmeter reading Answer: C
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Practice Mock Questions
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