Chapter 15: Fun with Magnets
Solved textbook questions with step-by-step explanations.
Grade 6 Q&A: Chapter 15: Fun with Magnets
Welcome to the Questions and Answers section for Grade 6 Environmental Studies (Part One), Chapter 15: "Fun with Magnets." This chapter introduces us to the exciting world of magnets, their properties, and their various uses in our daily lives. We will learn about magnetic and non-magnetic materials, the poles of a magnet, magnetic attraction and repulsion, and how a compass works.
Important Questions and Answers
Q1: What is a magnet?
Answer: A magnet is an object or a device that produces a magnetic field. It has the property of attracting certain materials like iron, nickel, and cobalt.
Q2: What are magnetic materials? Give examples.
Answer: Magnetic materials are substances that are attracted by a magnet. Examples include iron, nickel, cobalt, and steel.
Q3: What are non-magnetic materials? Give examples.
Answer: Non-magnetic materials are substances that are not attracted by a magnet. Examples include wood, plastic, glass, paper, copper, and aluminum.
Q4: What are the two poles of a magnet?
Answer: Every magnet has two poles: the North pole (N) and the South pole (S).
Q5: Where is the magnetic force strongest in a magnet?
Answer: The magnetic force is strongest at the poles of a magnet.
Q6: What happens when two like poles of magnets are brought near each other?
Answer: When two like poles (North-North or South-South) of magnets are brought near each other, they repel (push each other away).
Q7: What happens when two unlike poles of magnets are brought near each other?
Answer: When two unlike poles (North-South) of magnets are brought near each other, they attract (pull each other).
Q8: What is magnetic attraction?
Answer: Magnetic attraction is the force by which opposite poles of magnets pull towards each other, or a magnet pulls a magnetic material towards itself.
Q9: What is magnetic repulsion?
Answer: Magnetic repulsion is the force by which like poles of magnets push each other away.
Q10: What is a magnetic field?
Answer: A magnetic field is the area around a magnet where its magnetic force can be felt. It is an invisible field of force.
Q11: How can you find the poles of a magnet if they are not marked?
Answer: You can find the poles of an unmarked magnet by suspending it freely. The end that points towards the North direction is its North pole, and the end that points towards the South direction is its South pole.
Q12: What is a magnetic compass? How does it work?
Answer: A magnetic compass is a device used to find directions. It consists of a small, freely rotating magnet (needle) that always aligns itself in the North-South direction due to the Earth's magnetic field.
Q13: Why does a freely suspended magnet always point in the North-South direction?
Answer: A freely suspended magnet always points in the North-South direction because the Earth itself acts like a giant magnet, and its magnetic field interacts with the magnet, aligning it along the Earth's magnetic North-South axis.
Q14: List some common uses of magnets in daily life.
Answer: Magnets are used in refrigerators (to keep doors closed), speakers, electric motors, dynamos, toys, magnetic stickers, credit cards, and in separating magnetic waste from non-magnetic waste.
Q15: What is a temporary magnet? Give an example.
Answer: A temporary magnet is a magnet that retains its magnetism only for a short period or while it is under the influence of a magnetic field. An electromagnet is an example.
Q16: What is a permanent magnet? Give an example.
Answer: A permanent magnet is a magnet that retains its magnetism for a long period of time, even after the magnetizing force is removed. Bar magnets and horseshoe magnets are common examples.
Q17: How can a magnet be demagnetized?
Answer: A magnet can be demagnetized by heating it strongly, hammering it repeatedly, or dropping it from a height. This disorganizes the magnetic properties within the material.
Q18: What precautions should be taken while handling magnets?
Answer: Magnets should be kept away from electronic devices, mobile phones, computers, and credit cards, as their magnetic field can damage them. They should also be stored properly to prevent demagnetization.
Q19: Can a magnet attract non-magnetic materials?
Answer: No, a magnet cannot attract non-magnetic materials. It only attracts magnetic materials.
Q20: What is an electromagnet?
Answer: An electromagnet is a type of magnet in which the magnetic field is produced by an electric current. It is usually a temporary magnet, meaning the magnetism can be turned on and off.
Q21: How are electromagnets used in daily life?
Answer: Electromagnets are used in electric bells, loudspeakers, cranes for lifting heavy iron objects, and in various electronic devices.
Q22: What happens if a bar magnet is broken into two pieces?
Answer: If a bar magnet is broken into two pieces, each piece will act as a complete magnet with its own North and South poles. You cannot isolate a single pole.
Q23: How can you make a temporary magnet using a steel nail?
Answer: You can make a temporary magnet by rubbing a permanent magnet repeatedly in one direction over a steel nail. The nail will become magnetized for a short period.
Q24: Why is a compass useful for sailors and travelers?
Answer: A compass is useful for sailors and travelers because it helps them determine their direction (North, South, East, West) accurately, especially when there are no other landmarks available.
Q25: What is the principle behind magnetic levitation trains (Maglev trains)?
Answer: Magnetic levitation trains use the principle of magnetic repulsion. Powerful electromagnets lift the train above the tracks, reducing friction and allowing for very high speeds.
Q26: Why should magnets be stored properly?
Answer: Magnets should be stored properly (e.g., bar magnets with opposite poles facing each other, separated by a piece of wood, and horseshoe magnets with a keeper across their poles) to prevent them from losing their magnetism over time.
Q27: Can a magnet attract objects through a non-magnetic material?
Answer: Yes, a magnet can attract magnetic objects through non-magnetic materials like paper, plastic, or glass, as these materials do not block the magnetic field.
Exercise Solutions
Q1: Fill in the blanks.
- A magnet attracts objects made of iron.
- Every magnet has two poles: North and South.
- Like poles of magnets repel each other.
- Unlike poles of magnets attract each other.
- The magnetic force is strongest at the poles of a magnet.
Q2: True or False.
- Plastic is a magnetic material. False
- A freely suspended magnet points in the East-West direction. False (It points North-South)
- Heating a magnet can demagnetize it. True
- A compass is used to measure temperature. False (It is used to find direction)
- An electromagnet is a permanent magnet. False (It is a temporary magnet)
Q3: Answer the following questions.
- What is a magnet?
Answer: A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, and attracts or repels other magnets. - What are magnetic and non-magnetic materials? Give two examples of each.
Answer:- Magnetic Materials: Substances that are attracted by a magnet (e.g., iron, nickel, steel).
- Non-magnetic Materials: Substances that are not attracted by a magnet (e.g., wood, plastic, glass, paper).
- What happens when like poles of magnets are brought near each other?
Answer: When like poles (North-North or South-South) of magnets are brought near each other, they repel each other, meaning they push each other away. - What happens when unlike poles of magnets are brought near each other?
Answer: When unlike poles (North-South) of magnets are brought near each other, they attract each other, meaning they pull towards each other. - How does a magnetic compass work?
Answer: A magnetic compass works on the principle that a freely suspended magnet aligns itself with the Earth's magnetic field. The compass needle, which is a small magnet, rotates freely and its North pole always points towards the Earth's magnetic North pole, thus indicating direction.
Q4: Give reasons.
- A magnet attracts iron nails but not wooden pieces.
Reason: A magnet attracts iron nails because iron is a magnetic material, meaning it is susceptible to the magnetic force. Wooden pieces, on the other hand, are non-magnetic materials and are not affected by the magnetic field of a magnet. - A freely suspended magnet always rests in the North-South direction.
Reason: A freely suspended magnet always rests in the North-South direction because the Earth itself behaves like a giant magnet with its own magnetic field. The North pole of the suspended magnet is attracted to the Earth's magnetic South pole (which is near the geographic North pole), and its South pole is attracted to the Earth's magnetic North pole (which is near the geographic South pole), causing it to align along the Earth's magnetic axis. - Magnets should be kept away from electronic devices.
Reason: Magnets should be kept away from electronic devices like mobile phones, computers, and credit cards because their magnetic fields can interfere with or damage the sensitive electronic components or magnetic data stored on these devices, leading to malfunction or data loss.
References
- Maharashtra State Board Environmental Studies (Part One) Standard Six Textbook (2015 Edition) - Chapter 15: Fun with Magnets.
- Maharashtra State Board 6th Standard Environmental Studies Syllabus.
- Balbharati Environmental Studies Part 1 Textbook.