Exploring Magnets — Mastery

Q1. The ‘More to know!’ table on different magnet shapes includes Bar, Disc, Cylindrical, Ring and

• A. Pyramidal
• B. Conical
• C. Octagonal
• D. Spherical

Q2. Which sequence correctly describes how human use of magnets developed, according to the chapter?

• A. Lodestones → iron magnets → today's varied materials
• B. Iron magnets → lodestones → today's varied materials
• C. Today's varied materials → iron magnets → lodestones
• D. Lodestones → plastic magnets → iron magnets

Q3. From Table 4.1, which of these pairs is correctly described?

• A. Eraser — rubber, non-magnetic
• B. Pencil — wood, magnetic
• C. Paper-clip — plastic, magnetic
• D. Pencil — graphite, magnetic

Q4. A student has a magnet and a mixed pile of items: copper coin, iron nail, glass marble, steel safety pin, plastic clip. She brings the magnet near each. How many items will be attracted?

• A. One
• B. Four
• C. Three
• D. Two

Q5. ‘Most of the iron filings stick to the poles of a magnet of any shape.’ This means

• A. Only bar magnets have poles.
• B. Iron filings stick most to the middle of a ring magnet.
• C. Iron filings cannot stick to ring magnets.
• D. Poles exist on every magnet shape — bar, disc, ring, spherical — and the magnetic effect is strongest there.

Q6. Atharv rolls a bar magnet over a heap of steel U-clips and counts how many stick at each of three positions on the magnet (A and C are the ends, B is the middle). Which row of counts is the most likely observation?

• A. Position A: 10, Position B: 2, Position C: 10
• B. Position A: 10, Position B: 10, Position C: 2
• C. Position A: 2, Position B: 10, Position C: 10
• D. Position A: 10, Position B: 10, Position C: 10

Q7. After the compass needle has come to rest, the next step in using a compass is to

• A. Shake the compass to release the needle.
• B. Gently rotate the compass box until the N and S markings on the dial line up with the needle.
• C. Heat the compass box to remove humidity.
• D. Place the compass on top of a mobile phone.

Q8. The ‘Do you know?’ box describes an ancient Indian navigation device called the matsya-yantra. It was made of

• A. A wooden duck floating in a copper vessel
• B. A coconut shell with marked directions
• C. A clay compass with a feather pointer
• D. A magnetised fish-shaped iron piece floating in a vessel of oil

Q9. Compared with the matsya-yantra, the modern magnetic compass shown in Fig. 4.6 is different mainly because it

• A. Uses a magnet shaped like a needle that rotates on a pin, not a fish floating in oil.
• B. Uses a battery to keep working.
• C. Does not need any magnet at all.
• D. Works only at night.

Q10. Reshma has magnetised an iron sewing needle by repeated stroking with a bar magnet. To turn it into a working compass, she should

• A. Fix the needle horizontally through a small cork and float the cork on water in a bowl.
• B. Bury the needle in dry sand and watch it.
• C. Stick the needle to a wooden ruler with tape.
• D. Hang the needle inside a copper tube.

Q11. You are given a bar magnet whose poles are not marked. You also have a second bar magnet on which N and S are clearly painted. How can you identify the unmarked magnet's poles?

• A. Bring the marked N pole near one end of the unmarked magnet; if that end is repelled, it is the N pole.
• B. Bring the marked N pole near one end of the unmarked magnet; if that end is attracted, it is the N pole.
• C. Put both magnets in water; the unmarked one will float with its N pole upward.
• D. Heat the unmarked magnet; the cooler end is the N pole.

Q12. In Activity 4.5, magnet A is placed on five-six round pencils, and one end of magnet B is brought near one end of magnet A WITHOUT touching. Magnet A on the pencils begins to roll AWAY from B. The most likely cause is

• A. The pencils are slippery, so any object near A will push A away.
• B. Magnet B is heavier than A, so A automatically moves.
• C. The two ends facing each other are like poles, and the resulting repulsion pushes A away.
• D. Magnetic effect can cross air but not through magnet A.

Q13. If the South pole of a bar magnet is brought close to the North pole of a compass needle, the needle

• A. Moves away from the bar magnet
• B. Spins continuously
• C. Stays exactly still
• D. Moves towards the bar magnet

Q14. An unknown end of a bar magnet is brought near the North pole of a compass needle and the needle moves towards it. The unknown end must be a

• A. North pole
• B. Cannot be decided
• C. Non-magnetic end
• D. South pole

Q15. Which of these fun activities depends on the fact that magnetic effect can pass through a non-magnetic sheet?

• A. Floating a piece of iron in water
• B. Using two pencils to roll a magnet
• C. Painting the North pole of a magnet red
• D. Moving steel balls through a cardboard maze by sliding a magnet underneath

Q16. When storing two bar magnets together, the recommended arrangement is

• A. Place them end-to-end with like poles touching.
• B. Place them parallel to each other with unlike poles on the same side.
• C. Stack one above the other with no piece in between.
• D. Place them in a hot environment to keep them dry.

Q17. Between the two stored bar magnets, the chapter advises placing

• A. A piece of wood
• B. A piece of soft iron
• C. A piece of copper
• D. A piece of glass

Q18. Pieces of soft iron are placed across the ends of the stored bar-magnet pair because they

• A. Add weight so the magnets do not roll away
• B. Conduct electricity around the magnets
• C. Make the magnets shine
• D. Help complete the magnetic loop and protect the magnets from losing strength

Q19. All the rules in the ‘How to keep the magnets safe?’ box share one common purpose. They are designed to

• A. Save the magnets from physical or thermal shocks that would disturb their internal alignment
• B. Keep the magnets shiny and rust-free
• C. Increase the magnetic strength over time
• D. Make magnets attract a wider range of materials

Q20. In the ‘Magnetic garland’ activity (Fig. 4.11), a magnet seems to hold a garland in mid-air. The garland must be made of

• A. Flowers tied with cotton thread
• B. Small steel paper clips or iron pieces linked together
• C. Plastic beads only
• D. Coloured paper rolled into rings

Q21. In the maze game where the magnet is moved BELOW a cardboard tray to move steel balls ABOVE, the cardboard is acting as

• A. A non-magnetic material through which the magnetic effect passes
• B. A blocker that stops the magnetism
• C. A magnet itself
• D. An electric conductor

Q22. A steel paper-clip has fallen into a glass of water. Using only a bar magnet from outside, can the clip be picked up without getting fingers or the magnet wet?

• A. No — the water blocks the magnetism completely.
• B. Only with a U-shaped magnet.
• C. Only if hot water is used.
• D. Yes — the magnet's effect passes through the glass and the water, attracting the steel clip to the wall of the glass.

Q23. In the ‘Hopping frog’ activity, ring magnets are fixed along a scale in an alternating North–South fashion. The plastic strip carrying a frog hops as it slides over them because

• A. The plastic gets electrically charged.
• B. The ring magnet on the frog meets a same-pole-up region (repels — frog jumps), then an opposite-pole-up region (attracts — frog lands again).
• C. The frog is heated by friction with the strip.
• D. The scale's markings make the frog visually appear to hop.

Q24. The chapter asks students to find out about the Maglev train. The principle that allows the train to glide without touching the track is most closely related to

• A. Friction between rubber wheels and the track
• B. Repulsion between like poles of strong magnets on the train and the track
• C. Heat from the engine pushing the train up
• D. The Earth's gravity pulling the train sideways

Q25. A mechanic complains that steel screws keep falling off her screwdriver's tip. Using what you have learnt in the chapter, the best suggestion is

• A. Use a wooden screwdriver instead.
• B. Keep the screwdriver wet.
• C. Magnetise the metal tip of the screwdriver so it holds the steel screw.
• D. Use a copper screwdriver.

Q26. A Class 6 teacher wants children to construct understanding about magnetic and non-magnetic materials. Which is the most effective FIRST step?

• A. Define ‘magnetic material’ on the board before any activity.
• B. Dictate the names of three magnetic metals for students to memorise.
• C. Show a 10-minute video on magnets and follow with a quiz.
• D. Hand each pair of students a magnet and a tray of objects and ask them to predict and then test.

Q27. Activity 4.1 deliberately asks students to PREDICT before they test. The main learning purpose of asking for a prediction is to

• A. Save time during the activity
• B. Make children aware of their own existing ideas, which they can then check against observation
• C. Test how loudly children can speak
• D. Find out which child has the best handwriting

Q28. A Class 6 student insists that a copper coin should also be attracted by a magnet because ‘all metals are magnetic’. The best teacher response is to

• A. Tell the student they are wrong and move on.
• B. Mark the student's answer incorrect in the test and give the right answer.
• C. Set up a quick demonstration with copper, iron, and brass items so the student observes the difference firsthand, then discuss why.
• D. Ignore the misconception until the next chapter.

Q29. Before introducing the formal definition of ‘magnetic material’, a teacher asks her Class 6 students to list any place at home where they have seen a magnet. This question is good because it

• A. Tests whether the students have been doing homework
• B. Makes the lesson sound informal
• C. Saves chalk on the blackboard
• D. Activates students' everyday prior knowledge (pencil boxes, fridges, purses) so that new concepts are linked to familiar experiences

Q30. Tables 4.1, 4.2 and 4.3 in the chapter are best understood by the teacher as a tool for

• A. Formal end-of-term examination grading
• B. Comparison of student handwriting
• C. Decoration of the textbook
• D. Recording observations and organising data, which assesses students' science-process skills