Last Updated on August 22, 2025 by XAM CONTENT
Hello students, we are providing case study questions for class Class 8 Science. Case study questions are the new question format that is introduced in CBSE board. The resources for case study questions are very less. So, to help students we have created chapterwise case study questions for class Class 8 Science. In this article, you will find case study questions for cbse class Class 8 Science chapter 4 Electricity: Magnetic and Heating Effects.
| Chapter | Electricity: Magnetic and Heating Effects |
| Type of Questions | Case Study Questions |
| Nature of Questions | Competency Based Questions |
| Board | CBSE |
| Class | Class 8 |
| Subject | Maths |
| Useful for | Class 12 Studying Students |
| Answers provided | Yes |
| Difficulty level | Mentioned |
| Important Link | Class 11 Maths Chapterwise Case Study |
Case Study Questions on Electricity: Magnetic and Heating Effects
Case Study Question 1
Passage: The Science Exhibition and the Electromagnet
During a science exhibition, Sumana displayed a lifting electromagnet made with an iron nail wrapped in a wire connected to a battery. When she switched it ON, the nail picked up paper clips. When she switched it OFF, the clips fell down. Mohini and Aakarsh were amazed to see that electricity could create magnetism.
Q1.1 What scientific principle does this model demonstrate?
Q1.2 Why do the clips fall when the switch is turned OFF?
Q1.3 How does increasing the number of turns in the coil affect the electromagnet?
Q1.4 Name two devices in daily life that work on this principle.
Q1.5 Why are lifting electromagnets used in scrap yards?
Answer & Explanation:
- A1.1 The model demonstrates the magnetic effect of electric current.
- A1.2 When the current is switched OFF, the coil no longer produces a magnetic field, so the clips fall.
- A1.3 Increasing the number of turns strengthens the electromagnet, making it capable of lifting more objects.
- A1.4 Devices: electric bell, electric motor, loudspeakers.
- A1.5 Lifting electromagnets help move and sort heavy scrap iron/steel efficiently by switching the current ON/OFF.
Case Study Question 2
Passage: The Heating Wire Experiment
In an activity, a nichrome wire was connected to a cell and switch. On switching ON, the wire became warm. When two cells were used instead of one, the wire became hotter. Students realized that electrical energy was being converted into heat energy.
Q2.1 What effect of electric current is shown in this activity?
Q2.2 Why is nichrome used as a heating element in appliances instead of copper?
Q2.3 What happens if excessive current passes through a wire?
Q2.4 Mention two safety concerns linked with the heating effect of current.
Q2.5 List three appliances that use this effect in daily life.
Answer & Explanation:
- A2.1 This shows the heating effect of electric current.
- A2.2 Nichrome offers high resistance, so it converts more electrical energy into heat compared to copper.
- A2.3 Excessive current causes overheating, melting of insulation, and may lead to fire.
- A2.4 (i) Damage to plugs and sockets, (ii) Fire hazard due to overheating.
- A2.5 Examples: electric iron, kettle, room heater.
Case Study Question 3
Passage: Lemon Battery and Modern Cells
In an experiment, students made a lemon battery by inserting copper and iron electrodes into lemons. The LED glowed faintly when connected. Later, they compared it with dry cells and rechargeable batteries, which gave stronger power and lasted longer.
Q3.1 What is the principle behind the lemon battery?
Q3.2 Why does the LED glow only weakly with lemon cells?
Q3.3 Differentiate between dry cells and rechargeable batteries.
Q3.4 Why are rechargeable batteries considered environmentally friendly?
Q3.5 Give one modern advancement in rechargeable batteries.
Answer & Explanation:
- A3.1 The lemon acts as an electrolyte; a chemical reaction between metals (copper & iron) produces electricity.
- A3.2 Because lemon juice provides weak current, so the LED glows dimly.
- A3.3 Dry cells: single-use; Rechargeable batteries: can be reused multiple times.
- A3.4 They reduce waste, save money, and prevent toxic chemicals from polluting the environment.
- A3.5 Lithium-ion batteries and research on solid-state batteries are modern advancements.
We hope the given case study questions for Electricity: Magnetic and Heating Effects Class Class 8 helps you in your learning.
Also check
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- Curiosity Class 8 Science Chapter 2 The Invisible Living World Case Study Questions
- Curiosity Class 8 Science Chapter 1 Exploring the Investigative World of Science Case Study Questions
Topics from which case study questions may be asked
- Electric circuits and components
- Magnetic effects of electric current
- Electromagnets and their uses
- Electric bell mechanism
- Heating effect of current
- Fuses and safety devices
- Daily life applications
Electricity can produce both heat and magnetism, which are harnessed in countless devices from heaters to motors.
Frequently Asked Questions (FAQs) on Electricity: Magnetic and Heating Effects Case Study Questions
Q1: What is the magnetic effect of electric current?
A1: When current flows through a conductor, it produces a magnetic field around it, which can deflect a compass needle
Q2: Why are electromagnets preferred over permanent magnets in devices like cranes?
A2: Electromagnets can be switched ON and OFF, and their strength can be adjusted, making them more useful for lifting heavy materials
Q3: Why is nichrome used in heating appliances?
A3: Nichrome has high resistance and does not oxidize easily when heated, making it an ideal heating element
Q4: How does a dry cell differ from a Voltaic cell?
A4: A Voltaic cell uses a liquid electrolyte, whereas a dry cell uses a paste-like electrolyte, making it more portable and practical.
Q5: Why should used batteries not be thrown in normal garbage?
A5: Batteries contain harmful chemicals like acids, lead, and lithium which pollute soil and water. They should be disposed of in e-waste recycling facilities
Q6: Are there any online resources or tools available for practicing class 8 science curiosity “Electricity: Magnetic and Heating Effects” case study questions?
A6: We provide case study questions for CBSE Class 8 Science Curiosity on our website. Students can visit the website and practice sufficient case study questions and prepare for their exams. If you need more case study questions, then you can visit Physics Gurukul website. they are having a large collection of case study questions for all classes.
