Electrical Circuits Continued
Overview
How do you get exactly 3 volts out of a 9 volt battery for one part of a circuit? The answer is a potential divider, a pair of resistors that share out the voltage in proportion to their resistance. It is one of the neatest and most useful ideas in electronics.
In this lesson you will see why the voltage across a conductor grows with its resistance at constant current, learn how a variable potential divider works, and use the potential-divider equation to calculate the share of the voltage across each resistor. These ideas power the sensing circuits behind thermostats and light-controlled switches.
Objectives
- Know that the p.d. across an electrical conductor increases as its resistance increases for a constant current
- [Supplement] Describe the action of a variable potential divider
- [Supplement] Recall and use the equation for two resistors used as a potential divider R V 1 = 1 R V 2 2
Lesson Note
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.
Lesson Evaluation
Congratulations on completing the lesson on Electrical Circuits Continued. 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.
- Two equal resistors in series across a 12 V supply each have a voltage of: A. 3 V B. 6 V C. 12 V D. 24 V Answer: B
- In a potential divider, R1 = 200 ohm and R2 = 100 ohm across 9 V. The voltage across R1 is: A. 3 V B. 4.5 V C. 6 V D. 9 V Answer: C
- At constant current, the p.d. across a conductor is: A. inversely proportional to resistance B. proportional to resistance C. independent of resistance D. equal to the current Answer: B
- A variable potential divider is most easily made using a: A. fixed resistor B. potentiometer (slider) C. single wire D. battery only Answer: B
- Replacing one resistor in a divider with a thermistor makes the output voltage respond to: A. light B. sound C. temperature D. pressure Answer: C
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.
Recommended Books
Practice Mock Questions
Want to practice mock questions on Electrical Circuits Continued? Download the Green Bridge CBT app to access mock questions and full practice assessments for this topic.
Download The App On Google Playstore
Everything you need to excel in JAMB, WAEC & NECO
