Short Answer Questions
Q1 What did Magnes, the shepherd from Greece, discover?
Ans: Magnes discovered magnets when a stick with an iron cap attracted a piece of rock.
Q2: Name three magnetic materials mentioned in the chapter.
Ans: Iron, cobalt, and nickel are magnetic materials.
Q3: What are the two poles of a magnet called?
Ans: The two poles of a magnet are called the north pole (N) and the south pole (S).
Q4: How does a magnetic compass help in finding directions?
Ans: The needle in a compass points in the north-south direction, aligning with the Earth's magnetic field.
Q5: Can magnets attract non-metallic objects? Explain.
Ans: No, magnets attract only metallic objects, not non-metallic ones.
Long Answer Questions
Q1: Explain the directive property of a magnet. How does it relate to a compass?
Ans: The directive property of a magnet is its ability to align in the north-south direction. A compass uses this property, as the needle, being a magnet, points north-south due to Earth's magnetic force.
Q2: Describe the interaction of magnets. What happens when like poles are brought close? What about unlike poles?
Ans: Like poles repel each other, moving away. Unlike poles attract, moving closer to each other.
Q3: How can an ordinary iron needle become a temporary magnet? Explain the touch-and-stroke method.
Ans: Stroking a magnet on an iron needle in one direction aligns its molecules, making it a temporary magnet through the touch-and-stroke method.
Q4: Why is it said that the two poles of a permanent magnet cannot be separated even by cutting?
Ans: Cutting a magnet into pieces results in each piece becoming a separate magnet, each with its north and south pole.
Q5: Discuss the uses of magnets mentioned in the chapter. Provide at least three examples.
Ans: Magnets are used in compasses, toys, telephones, doorbells, headphones, televisions, digital cameras, computers, refrigerators, and in credit/debit card strips. In industries, magnets are used to separate metal objects for recycling.
