RBSE Solutions Class 6 Science Chapter 13 Magnetism

Activities

 

Activity - 2 (Page 113)

🎯 Exam Tip: When following activity instructions, read each step carefully and ensure you have all the necessary materials.

 

Question 1. Are the iron filings evenly attracted by the magnet?
Answer: No, the iron filings are not attracted evenly across the magnet. Instead, the iron filings gather mostly at the two ends of the magnet. These special areas at the ends are known as the poles of the magnet, where the magnetic force is strongest.
In simple words: The iron filings stick mostly to the very ends of the magnet, not everywhere else. These strong spots are called the poles.

🎯 Exam Tip: Always describe the observation accurately. Iron filings concentrate at the poles, showing that magnetic strength is highest there, which is a key property of magnets.

 

Activity - 3 (Page 113)

🎯 Exam Tip: When doing experiments with magnets, always make sure there are no other magnetic materials nearby that could interfere with your results.

 

Question. Which end of the magnet is north pole and which south pole?
Answer: When a magnet is suspended freely, one end will always point towards the North direction. This end is called the north pole of the magnet. The opposite end, which points towards the South direction, is known as the south pole or south-seeking pole. This property helps us find directions.
In simple words: The end of a free-hanging magnet that points North is its north pole. The other end, which points South, is its south pole.

🎯 Exam Tip: Remember that a freely suspended magnet always aligns itself with Earth's magnetic field, pointing North-South, which is how a compass works.

 

Activity - 4

🎯 Exam Tip: When performing experiments involving suspension, ensure the setup is stable and free from air currents to get accurate readings.

 

Question 1. What do you observe?
Answer: When the south pole of another magnet is brought close to the south pole of the suspended magnet, the suspended magnet moves away. This movement backward is a clear sign of repulsion, meaning like poles push each other apart. This shows that similar poles do not attract.
In simple words: When two south poles come close, they push each other away. This pushing away is called repulsion.

🎯 Exam Tip: Always describe the direction of movement clearly (e.g., "moves backward" or "moves away") to indicate repulsion.

 

Question 2. What do you observe this time?
Answer: This time, when the south pole of the other magnet is brought near the north pole of the suspended magnet, the suspended magnet moves closer. It even sticks to the other magnet. This action is called attraction, which happens when opposite poles are brought together. This demonstrates that unlike poles pull each other together.
In simple words: When a south pole and a north pole come close, they pull each other together. This pulling is called attraction.

🎯 Exam Tip: Clearly distinguish between attraction (pulling together) and repulsion (pushing away) and relate them to opposite and like poles, respectively.

 

Question 3. What properties of a magnet do you find from this activity?
Answer: From this activity, we learn two main properties of magnets: first, that similar poles (like North-North or South-South) repel each other, pushing away. Second, that opposite poles (like North-South) attract each other, pulling together. This fundamental behavior is why magnets are so useful in many devices. These forces are strongest at the poles.
In simple words: We learn that magnets push away poles that are the same and pull together poles that are different.

🎯 Exam Tip: When asked for properties, always state them clearly and briefly, emphasizing "like poles repel" and "unlike poles attract" as key takeaways.

 

Question 1. Do safety pins attract towards nail?
Answer: Yes, the safety pins are attracted towards the iron nail. This happens because the iron nail has been rubbed with a magnet repeatedly in one direction, causing it to gain magnetic properties itself. It has now become a temporary magnet.
In simple words: Yes, the safety pins stick to the nail. This is because rubbing the nail with a magnet made the nail also act like a magnet.

🎯 Exam Tip: When demonstrating induced magnetism, ensure the nail is rubbed in a single direction to align the magnetic domains effectively.

 

Activity - 6 (Page 115)

🎯 Exam Tip: When making an electromagnet, always use an insulated wire to prevent short circuits and ensure safety.

 

Question 1. Are the safety pins attracted towards the iron nail?
Answer: Yes, the iron nail attracts the safety pins when the copper wire wrapped around it is connected to a battery. This is because the electric current flowing through the wire turns the iron nail into a temporary magnet, also known as an electromagnet. The magnetic field created by the current allows it to attract magnetic objects.
In simple words: Yes, the nail pulls the safety pins. When electricity flows through the wire wrapped around the nail, the nail becomes a magnet and can attract things.

🎯 Exam Tip: Clearly state that the nail becomes a magnet only when current flows, highlighting the temporary nature of an electromagnet.

 

Question 2. Are the iron filings or safety pins attracted towards the iron nail this time?
Answer: No, this time the iron nail is not able to attract the safety pins. This is because once the wire is disconnected from the battery, the electric current stops flowing, and the iron nail loses its magnetic properties. Electromagnets only work when electricity is passing through them.
In simple words: No, the pins do not stick to the nail anymore. Once the electricity is off, the nail stops being a magnet.

🎯 Exam Tip: Emphasize that electromagnets are temporary and their magnetism can be controlled by switching the electric current on or off.

 

Exercises

 

Choose the correct answer from the following

 

Question 1. Magnetic material from the following is
(a) cobalt
(b) copper
(c) glass
(d) wood
Answer: (a) cobalt
In simple words: Cobalt is a type of metal that a magnet can attract, making it a magnetic material. Other options like copper, glass, and wood are not attracted by magnets.

🎯 Exam Tip: Remember common magnetic materials like iron, nickel, and cobalt. Non-magnetic materials are not attracted by magnets.

 

Question 2. A magnet has poles
(a) one
(b) two
(c) three
(d) four
Answer: (b) two
In simple words: Every magnet, no matter how small, always has two ends called poles: a north pole and a south pole.

🎯 Exam Tip: Magnets always have two poles (North and South), even if you break them into smaller pieces, each piece will still have two poles.

 

Question 4. Where is an electric crane used?
(a) to dig a pit
(b) to lift big stones
(c) to lift heavy objects made of iron
(d) None of the options
Answer: (c) to lift heavy objects made of iron
In simple words: Electric cranes use strong electromagnets to pick up and move heavy things made of iron, like scrap metal.

🎯 Exam Tip: Electric cranes use electromagnets because their magnetic strength can be turned on and off, allowing them to pick up and release objects easily.

 

Fill in the blanks

 

Question 1. A magnet has a.... pole and a pole.
Answer: A magnet has a **North** pole and a **South** pole. These two poles are always present together in a magnet. It's impossible to have a magnet with just one pole, as they always come in pairs.
In simple words: A magnet always has two ends, one called North and the other called South.

🎯 Exam Tip: Remember that magnets always have a North and South pole; you can't separate them, even by breaking the magnet.

 

Question 2. Man made magnets are called ........
Answer: Man-made magnets are called **artificial magnets**. These magnets are specially created by people using different materials and methods, unlike natural magnets found in nature. Examples include bar magnets and horseshoe magnets.
In simple words: Magnets made by people are called artificial magnets.

🎯 Exam Tip: Distinguish between natural magnets (like lodestone) and artificial magnets (which are manufactured for specific uses).

 

Question 3. Pieces of ........ are attracted towards a magnet?
Answer: Pieces of **iron** are attracted towards a magnet. Magnets are special because they can pull certain metals, like iron, nickel, and cobalt, towards them. This pull is called magnetic attraction.
In simple words: Magnets pull on things made of iron.

🎯 Exam Tip: Keep in mind that not all metals are magnetic; only specific ones like iron, nickel, and cobalt are strongly attracted to magnets.

 

Question 4. ........ takes place between similar poles of two magnets.
Answer: **Repulsion** takes place between similar poles of two magnets. This means that if you bring two north poles together, they will push each other away. The same happens if you bring two south poles together. This is a basic rule of magnetism.
In simple words: When two like poles of magnets meet, they push each other away. This is called repulsion.

🎯 Exam Tip: The principle of "like poles repel, unlike poles attract" is fundamental to understanding how magnets work.

 

Short Answer Questions

 

Question 1. What is a magnet?
Answer: A magnet is a special material that can attract objects made of certain metals, like iron, cobalt, and nickel. This ability to pull things is called magnetism. Magnets have an invisible force field around them.
In simple words: A magnet is a material that pulls on objects made of iron, cobalt, and nickel.

🎯 Exam Tip: Define a magnet by its key property: the ability to attract specific ferromagnetic materials, and mention common examples.

 

Question 2. In which direction a freely suspended magnet comes to rest?
Answer: Magnets are used in speakers and in electronic bells. These devices rely on the magnetic field to create sound or movement. Speakers use magnets to convert electrical signals into sound waves, while electronic bells use them to make a hammer strike a gong.
In simple words: Magnets are used in things like speakers to make sound and in electronic bells to ring.

🎯 Exam Tip: When listing uses of magnets, focus on examples where their attractive or repulsive forces are put to work, such as in motors, generators, and everyday appliances.

 

Question 4. What will happen if a magnet is heated?
Answer: If a magnet is heated, it will lose its property of magnetism. High temperatures cause the tiny magnetic parts inside the magnet to get disordered, making the magnet weaker or even stopping it from being a magnet altogether. This process is called demagnetization.
In simple words: If you heat a magnet, it stops being magnetic. The heat mixes up its small magnetic parts.

🎯 Exam Tip: Heating, hammering, or dropping a magnet can cause it to lose its magnetic strength, so handle magnets carefully.

 

Question 5. Draw a well labelled diagram of a compass.
Answer:
The diagram shows a simple compass, which is a key tool for finding directions. It has a small magnetized needle that spins freely, enclosed in a protective case with direction markings.
In simple words: A compass has a needle that points North and South, inside a round case, to help us find directions.

🎯 Exam Tip: When drawing a compass, ensure the needle is labeled with North (N) and South (S) poles and it's shown pivoted at the center, resting in the N-S direction.

 

Long Answer Type Questions

 

Question 1. With the help of a diagram explain how to make an electromagnet?
Answer:
To create an electromagnet, first take an iron nail and wrap an insulated copper wire tightly around it in a coil, like a spring. Then, connect both ends of the copper wire to the terminals of a battery. When electricity flows from the battery through the coiled wire, the iron nail becomes magnetized. This temporary magnet can now attract small magnetic items, such as iron filings or safety pins. However, once the connection to the battery is broken, the current stops, and the iron nail quickly loses its magnetism, showing that electromagnets are temporary. This allows for controlled magnetic effects in various applications.
In simple words: Wrap a wire around an iron nail and connect it to a battery. The nail becomes a magnet and can pick up small metal items. When you disconnect the battery, it stops being a magnet.

🎯 Exam Tip: When explaining how to make an electromagnet, clearly state the role of the iron core, the insulated wire coil, and the battery as the power source, and highlight the temporary nature of the magnetism.

 

Question 2. Suggest an activity to explain that similar poles of a magnet repel each other whereas opposite poles of a magnet attract each other. Draw necessary diagrams also.
Answer: To show how magnets attract and repel, you can perform this activity:

1. First, tie a thread around the middle of a bar magnet and hang it from a stand so it can swing freely. Let it settle completely.
2. Now, take another bar magnet. Bring its south pole close to the south pole of the suspended magnet. You will notice that the suspended magnet moves backward, pushing away from the magnet you are holding. This movement shows repulsion between like poles.
3. After that, take the same magnet and bring its north pole close to the south pole of the suspended magnet. This time, the suspended magnet moves closer and even sticks to the magnet you are holding. This movement demonstrates attraction between unlike poles.

These observations clearly show that magnets with similar poles (North-North or South-South) repel each other, while magnets with opposite poles (North-South) attract each other. This is a key principle in how magnets interact.
In simple words: Hang one magnet freely. Bring another magnet's south pole to the hanging magnet's south pole; they push away (repel). Then, bring the second magnet's north pole to the hanging magnet's south pole; they pull together (attract). This proves that like poles push apart, and unlike poles pull together.

🎯 Exam Tip: When describing magnet interactions, always specify which poles are being brought together (e.g., "south pole to south pole") and clearly state the resulting action (attraction or repulsion).

 

Other Important Questions

 

Multiple choice Questions

 

Question 1. Magnetic material is
(a) copper
(b) nickel
(c) silver
(d) platinum
Answer: (b) nickel
In simple words: Nickel is a metal that magnets can attract, making it a magnetic material. Copper, silver, and platinum are not magnetic.

🎯 Exam Tip: Remember that iron, nickel, and cobalt are the primary magnetic materials. Other metals are generally non-magnetic or only weakly magnetic.

 

Question 3. The needle of the compass made of
(a) magnetic
(b) copper
(c) silver
(d) glass
Answer: (a) magnetic
In simple words: The needle inside a compass is made from a magnetic material so it can react to Earth's magnetic field and point North.

🎯 Exam Tip: The compass needle must be made of a magnetic material (usually iron or steel) to align itself with Earth's magnetic field, allowing it to indicate direction.

 

Question 4. When two like poles of magnet are bring near to each other.
(a) they attract
(b) they repel
(c) first attract and then repel
(d) All of the options
Answer: (b) they repel
In simple words: When two ends of magnets that are the same (like two North poles) are put close, they push each other away.

🎯 Exam Tip: Always remember the fundamental rule: like poles repel, and unlike poles attract. This is crucial for understanding magnetic interactions.

 

Question 5. Magnet is used in
(a) electric bell
(b) electric motor
(c) compass
(d) All of the options
Answer: (d) All of the options
In simple words: Magnets are used in many devices like electric bells, electric motors, and compasses because of their special attractive and repulsive forces.

🎯 Exam Tip: Be able to list several practical applications of magnets, understanding how their properties are utilized in each device.

 

Question 4. We can make magnet by ........ methods.
Answer: We can make a magnet by **rubbing** methods, using **electric current**, or by **induction**. These are common ways to create artificial magnets. The rubbing method involves stroking a magnetic material with an existing magnet, while electric current can create electromagnets.
In simple words: You can make a magnet by rubbing it with another magnet or by using electricity.

🎯 Exam Tip: State the common methods for making magnets (rubbing, electrical, induction) and briefly describe one method if asked.

 

Very Short Answer Type Questions

 

Question 1. Why the stick of shepherd is attracted by the rock?
Answer: The stick of the shepherd was attracted by the rock because there was a magnetic substance underneath the rock. This rock was likely a natural magnet (like lodestone) that pulled on the iron tip of his stick. Natural magnets are found in the Earth's crust.
In simple words: The rock had something magnetic inside it that pulled the shepherd's stick.

🎯 Exam Tip: When explaining magnetic attraction, identify both the magnetic material and the object it is attracting.

 

Question 2. How many poles do a bar magnet have?
Answer: A bar magnet always has two poles. These are known as the North pole and the South pole. Even if you break a bar magnet into smaller pieces, each piece will still have its own North and South poles. This is a fundamental property of all magnets.
In simple words: A bar magnet always has two poles: a North pole and a South pole.

🎯 Exam Tip: State the exact number of poles (two) and their names (North and South) when discussing magnet poles.

 

Question 3. Name the two poles of the magnet.
Answer: The two poles of a magnet are the North pole and the South pole. These names come from the fact that a freely suspended magnet's ends point roughly towards the Earth's geographic North and South. The North pole of a magnet is often colored red or marked with 'N'.
In simple words: The two ends of a magnet are called the North pole and the South pole.

🎯 Exam Tip: Clearly name both poles as North pole and South pole; avoid confusion with geographical directions.

 

Question 4. Which type of magnet is in the speaker.
Answer: A speaker usually contains a **spherical magnet** or a ring magnet, specifically a permanent magnet. This magnet works with a coil of wire to produce sound by converting electrical signals into vibrations. The magnet's strong, steady field is essential for this process.
In simple words: Speakers have a round or spherical magnet inside that helps make sound.

🎯 Exam Tip: For speaker magnets, remember they are typically permanent magnets and their interaction with an electric coil is what creates sound vibrations.

 

Question 5. What is a cam – pass?
Answer: A compass is an instrument used to find direction. It has a small, lightweight magnet (the needle) that is allowed to turn freely. This needle always aligns itself with the Earth's magnetic field, pointing towards the magnetic North and South poles. This simple device is vital for navigation.
In simple words: A compass is a tool that helps you find directions by showing you which way is North.

🎯 Exam Tip: Define a compass by its function (finding direction) and its key component (a freely moving magnetic needle).

 

Short Answer Type Questions

 

Question 1. Based on the nature of the magnet how many types of substances are?
Answer: Based on how they react to a magnet, substances are generally divided into two main types:
1. **Magnetic substances:** These are materials that are attracted to a magnet. They can also be magnetized themselves.
    Example: Iron, cobalt, nickel.
2. **Non-Magnetic substances:** These are materials that are not attracted to a magnet and cannot be easily magnetized.
    Example: Plastic, glass, wood, leather, etc.
Understanding these types helps explain why magnets only stick to certain objects.
In simple words: There are two kinds of things based on magnets: magnetic ones (like iron) that stick to magnets, and non-magnetic ones (like wood) that don't.

🎯 Exam Tip: Clearly list both types of substances and provide at least two examples for each category to illustrate the concept.

 

Question 2. Write properties of magnet.
Answer: Here are some key properties of magnets:
1. A freely suspended magnet always comes to rest pointing in the North-South direction. This property is used in compasses.
2. Magnets only attract magnetic materials (like iron, nickel, cobalt) and not non-magnetic materials.
3. There is attraction between unlike poles of a magnet (North attracts South) and repulsion between like poles (North repels North, South repels South).
These properties are fundamental to how magnets work and are used in various applications.
In simple words: Magnets always point North-South when free, only pull on special metals, and poles that are different attract while poles that are the same push away.

🎯 Exam Tip: When listing properties, include the directional property, the attraction of magnetic materials, and the law of attraction/repulsion between poles.

 

Question 3. Draw different types of artificial magnets.
Answer:

Artificial magnets come in various shapes designed for specific uses. The most common types include the Horse-shoe magnet, which is U-shaped and has poles close together for a strong field; the Bar magnet, a simple rectangular shape; and the Cylindrical magnet, which is round and elongated. Each shape has its advantages depending on the application.
In simple words: People make magnets in different shapes like U-shaped (horse-shoe), long rectangular (bar), and round rod (cylindrical).

🎯 Exam Tip: When drawing magnets, ensure the poles (N and S) are clearly labeled on each shape, as this is crucial for understanding their function.

 

Question 4. How can you handle a magnet.
Answer: To ensure magnets retain their strength and last longer, they should be handled with care:
1. Bar magnets should be kept in pairs with their unlike poles on the same side, separated by pieces of wood, and with soft iron keepers across the ends. This helps maintain their magnetism.
2. Avoid dropping magnets, hammering them, or heating them strongly, as these actions can cause them to lose their magnetic properties.
3. Store them away from electronic devices like mobile phones, computers, and TVs, as magnets can interfere with their functioning.
Following these rules helps keep magnets strong and useful for a long time.
In simple words: Keep bar magnets in pairs with unlike poles facing each other and soft iron pieces at the ends. Do not drop, hit, or heat magnets, and keep them away from electronics.

🎯 Exam Tip: Always store magnets properly to prevent demagnetization. Using keepers and keeping unlike poles together helps preserve their magnetic strength.

 

Long Answer Type Questions

 

Question 1. Write a brief summary about discovery of magnet.
Answer: The discovery of magnets is often linked to an old story about a shepherd named Magnus in ancient Greece. He used to take his sheep and goats to graze near a mountain, carrying a stick with a small iron piece at its end. One day, his stick got stuck to a rock, and he had to pull very hard to free it. He was surprised because it felt like the rock was pulling his stick. It turned out that this particular rock was a natural magnet, possessing the ability to attract iron. This accidental discovery is how natural magnets, also known as lodestones, are said to have been found. This fascinating property of attraction led to many further discoveries and uses of magnets.
In simple words: A shepherd named Magnus found his iron-tipped stick sticking to a rock in Greece. This rock was a natural magnet, and this is how magnets were discovered by chance.

🎯 Exam Tip: When narrating the discovery of magnets, mention the shepherd Magnus and the key observation of his iron-tipped stick sticking to a magnetic rock.

 

Question 2. Describe the structure of a compass.
Answer: A compass is typically a small, round box with a transparent glass cover on top. Inside this box, there is a small, lightweight magnetized needle. This needle is balanced on a pivot point, allowing it to rotate freely. One end of the needle is the north pole, and the other is the south pole. The compass also has a dial with direction markings like North (N), South (S), East (E), and West (W). When placed on a flat surface, the magnetic needle aligns itself with the Earth's magnetic field, with its north pole indicating the magnetic North direction. This simple yet effective design makes it a vital tool for navigation.
In simple words: A compass is a small box with a clear top and a magnetic needle inside. This needle spins to point North and South, helping us find directions.

🎯 Exam Tip: When describing a compass, mention the key components: a magnetic needle, a pivot, a clear cover, and direction markings on the dial.

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