Class 9 Science Chapter 4: Exploring Magnets – Previous Year Questions with Solutions (2020–2025)

Many Class 9 students spend weeks reviewing Chapter 4 notes repeatedly, hoping the content will 'stick'—but this passive approach wastes time and builds false confidence. Previous year questions force active recall: you must retrieve specific facts (e.g., 'north pole of a magnet repels the north pole of Earth's magnetic field') under exam conditions, identify what the question is really asking, and articulate your answer in 1–5 mark formats. Research shows spaced retrieval practice improves long-term retention by 40–60% compared to passive review. PYQs simulate real exam stress: you learn pacing (how to fit a 3-mark answer in 6–7 minutes), recognise distractor options in MCQs, and spot your weak spots (e.g., 'Can I clearly explain why a compass needle aligns with Earth's magnetic field?'). Additionally, CBSE examiners recycle core concepts—questions on poles, magnetic attraction, and magnet-making appear nearly every year in slightly different wording. By solving past papers, you internalize these patterns and build exam muscle memory. Finally, working solutions reveal the exact depth and language CBSE expects: a 1-mark answer must be precise; a 5-mark answer must include a diagram, working, and clear logic. Guessing is replaced by strategy.

1-mark questions test definitional clarity and quick recall. These five appear frequently: **Q1. What do you mean by a magnetic material?** A: A magnetic material is a substance that is attracted by a magnet or can be magnetized. Examples: iron, cobalt, nickel. Non-magnetic materials (e.g., wood, plastic, glass) are not attracted by magnets. **Q2. Name the two poles of a magnet.** A: The two poles are north pole and south pole. Like poles repel each other; opposite poles attract. **Q3. What is a compass?** A: A compass is a device consisting of a magnetized needle that rotates freely on a pivot. It aligns with Earth's magnetic field to indicate geographical direction (north–south). **Q4. Why does a freely suspended magnet always align in the north–south direction?** A: Because Earth itself acts as a giant magnet with a magnetic field. A freely suspended magnet aligns its north pole towards Earth's magnetic south pole (near the geographic North Pole). **Q5. Define 'magnetic field'.** A: A magnetic field is the region around a magnet where its magnetic influence can be detected. It exerts force on other magnets or magnetic materials entering that region. Represented by field lines radiating from poles. Each answer is concise, NCERT-exact, and avoids unnecessary elaboration—exactly what 1-mark graders expect.

3-mark questions blend recall with explanation or simple application. Expect a definition plus a reason or example. **Q1. Distinguish between magnetic and non-magnetic materials with one example each.** A: Magnetic materials are attracted by magnets and can be magnetized; examples: iron, steel, nickel. Non-magnetic materials are not attracted by magnets and cannot be magnetized; examples: wood, rubber, glass. This is why iron nails are used to make electromagnets, but rubber is used for insulation. **Q2. Explain what happens when two bar magnets are placed with their north poles facing each other. Draw a simple diagram.** A: The two north poles repel each other—a repulsive force pushes them apart. This occurs because the magnetic field lines from one north pole cannot overlap with field lines from the other; they repel. Diagram: Two bar magnets side by side with the N poles facing inward; arrows pointing outward from each magnet show repulsion. (The diagram is essential for full marks.) **Q3. How does a compass needle help determine geographical directions?** A: A compass contains a magnetized needle that aligns freely with Earth's magnetic field. The needle's north pole points towards Earth's magnetic south pole (near geographic North Pole), and the south pole points towards Earth's magnetic north pole (near geographic South Pole). By observing the needle's alignment, we can determine all four cardinal directions. **Q4. Explain the process of making an artificial magnet by stroking a steel bar with a permanent magnet.** A: When a steel bar is stroked repeatedly in one direction with a permanent magnet, the magnetic domains inside the steel align in the same direction. This alignment magnetizes the steel bar, converting it into an artificial magnet. The end that was last stroked by the north pole of the permanent magnet becomes the south pole of the new magnet, and vice versa. **Q5. Why do magnetic field lines never intersect each other?** A: Magnetic field lines represent the direction of magnetic force at each point in space. If two field lines were to intersect, it would mean the magnetic force has two different directions at that point, which is physically impossible. Therefore, field lines cannot intersect; they form closed loops from north to south pole. Each 3-mark answer includes a reason (the 'why'), making it suitable for board marking schemes.

5-mark questions demand full explanations, diagrams, and sometimes multi-step reasoning. These three are common: **Q1. Explain the properties of a magnet and describe how Earth's magnetism is related to these properties.** Full Answer: Properties of a magnet: (i) A magnet has two poles: north and south. (ii) Like poles repel; opposite poles attract. (iii) Magnetic field lines emerge from the north pole and enter the south pole. (iv) A magnet cannot be isolated to a single pole (if broken, each piece becomes a magnet). Earth's Magnetism: Earth behaves like a giant bar magnet with a magnetic field extending to space. The magnetic south pole is near the geographic North Pole, and the magnetic north pole is near the geographic South Pole (approximately 11.5° misaligned from the rotational axis). This causes a freely suspended magnet or compass needle to align in the north–south direction. The strength of Earth's magnetic field is relatively weak (about 25–65 microtesla) but sufficient to orient compasses and migrating animals. This field is believed to be generated by convection currents in Earth's liquid iron outer core. Diagram: A cross-section of Earth showing the magnetic poles, magnetic field lines, and a compass needle aligning with the field. **Q2. Describe an experiment to demonstrate magnetic attraction and repulsion using two bar magnets. What conclusions can you draw?** Full Answer: Experiment Setup: – Take two bar magnets and label their poles (N and S) clearly. – Place one magnet on a frictionless surface or suspend it by a string. – Slowly bring the second magnet near it from different directions. Observations: (a) When the north pole of the first magnet approaches the north pole of the second, they repel (push apart). (b) When the north pole approaches the south pole, they attract (pull together). (c) The force increases as the magnets come closer (inverse square relationship: F ∝ 1/r²). Conclusions: 1. Like poles repel; opposite poles attract. 2. Magnetic force is a non-contact force (acts without physical touch). 3. The magnitude of the force depends on the distance between poles. 4. Every magnet has exactly two poles; there are no monopoles. Diagram: Show four scenarios—N–N (repulsion with arrows pointing away), N–S (attraction with arrows pointing towards each other), S–S (repulsion), and S–N (attraction). **Q3. Explain the method of making an artificial magnet by electrical method (electromagnet). What are its advantages over a permanent magnet?** Full Answer: Electromagnet Method: – Wrap an insulated copper wire around an iron core (soft iron rod or nail) in a tight coil. – Connect the wire to a battery through a switch and rheostat (variable resistor). – When the switch is closed, current flows through the coil, creating a magnetic field around the iron core. – The iron core is magnetized and becomes an electromagnet. – When the switch opens, the current stops, and the magnetic field disappears (the iron core loses magnetism because soft iron does not retain magnetization). Mathematical Relation: The magnetic field strength is proportional to the number of coils (N) and the current (I): B ∝ NI. Advantages of Electromagnets over Permanent Magnets: 1. Magnetic field strength can be controlled by adjusting current or resistance. 2. The magnetic field can be switched on and off instantly. 3. The polarity can be reversed by reversing current direction. 4. Can be made very powerful (e.g., in MRI machines, industrial cranes). 5. Suitable for applications requiring variable magnetism (door locks, doorbells, relays). Disadvantages: – Requires continuous electrical power. – Generates heat (I²R losses in the coil). Diagram: Show a coil around an iron rod, connected to a battery, switch, and rheostat. Label the north and south poles of the electromagnet. These 5-mark answers require approximately 12–15 minutes to write under exam conditions and should occupy about one full page of the answer sheet.

The 2024–25 CBSE rationalized syllabus maintains Chapter 4: Exploring Magnets as core content, but the assessment pattern shows subtle shifts worth noting: **Increased Focus on Application & Real-World Links:** Recent years show fewer pure 'definition' 1-mark questions and more application-based asks: 'Why does Earth's magnetic field deflect at the poles?' or 'How does a maglev train use magnetic repulsion?' Prepare by linking concepts to everyday examples. **Emphasis on Diagram Interpretation:** Questions now frequently present unlabeled magnetic field diagrams and ask students to identify pole positions or predict attraction/repulsion. Practice sketching and interpreting field line patterns—this skill is now weighted in 3-mark and 5-mark questions. **Integration with Other Chapters:** Magnetism is increasingly cross-linked with Chapter 3 (Current Electricity). Expect questions like 'How does current in a coil create a magnetic field?' or 'Why is soft iron preferred over hard steel for electromagnet cores?' This bridge requires understanding both circuits and magnetic domains. **Reduced Weight on 'Construction' of Magnets:** While making electromagnets remains core, the detailed step-by-step procedures (e.g., stroking method) are now tested more conceptually than procedurally. Focus on *why* the process works (domain alignment) rather than exact stroke counts. **New Question Types:** Expect more 'analyse and explain' questions requiring students to interpret experimental data or diagrams and deduce magnetic properties. Multiple-choice options now feature scientifically plausible distractors rather than obviously wrong answers. **CBSE-Aligned Preparation Tip:** Instead of memorizing steps, build conceptual maps: 'magnetic domains → aligned domains = permanent magnet' and 'current in coil → magnetic field → electromagnet.' This deeper understanding prepares you for pattern-shifted questions.

**Time Allocation:** If magnets appears as a full question paper (say, 3–4 questions worth 12–15 marks): – 1-mark questions: 1 minute per question (read → recall → write). – 3-mark questions: 6–7 minutes each (read → think → plan diagram → write + explain). – 5-mark questions: 12–14 minutes (read → plan full solution → write + diagram). **Step-by-Step Approach:** 1. **Read the Entire Question First.** Underline key words: 'explain,' 'distinguish,' 'draw,' 'with reason.' This signals answer depth required. 2. **For 1-Mark Questions:** Use textbook language. 'A magnet has two poles' is acceptable; 'Magnets have north and south poles that push and pull' is vague. Be precise. 3. **For 3-Mark Questions:** Always provide a reason (linked with 'because' or 'due to'). If a diagram is asked, allocate 2–3 minutes to draw it clearly; diagrams earn easy marks. Label poles, forces, and field directions. 4. **For 5-Mark Questions:** Outline your answer in the margin first (e.g., 'Defn → Property 1 → Property 2 → Example → Diagram'). This prevents mid-answer confusion. Allocate 3 minutes to a clean, labeled diagram. 5. **Common Mistakes to Avoid:** – Confusing Earth's magnetic north pole (near geographic South Pole) with geographic north. Examiners heavily penalize this. – Saying 'south pole of Earth is near the North Pole'—state it precisely as 'magnetic south pole.' – Drawing magnetic field lines crossing—they never do. – Forgetting that breaking a magnet produces two new magnets, not a monopole. 6. **Diagram Best Practices:** Always show poles (N/S labels), field line direction (dots and crosses for into/out of page, or arrows along lines), and any forces (attraction as arrows towards each other, repulsion as arrows away). A clear diagram can earn 1–2 bonus marks on a 5-mark question. 7. **If Unsure:** Write what you know (domain alignment, pole properties, Earth's field) rather than leaving blank space. Partial credit is awarded for conceptual understanding even if the full answer is incomplete. 8. **Last 2 Minutes:** Quickly re-read your 5-mark answer. Did you define terms? Did you explain the 'why'? Did you include a diagram? These are the NCERT checklist items examiners look for. **Confidence Builder:** Start a 3-day free trial at cbsetutor.ai to practice past papers under timed conditions and receive instant feedback on diagram quality and explanation depth—two skills that classrooms rarely emphasize but boards heavily reward.

Print or write down these Chapter 4 essentials and verify you can answer each without notes: ✓ Define: magnetic material, non-magnetic material, magnetic field, compass, electromagnet. ✓ State the properties of magnets (two poles, like poles repel, field lines, non-isolation of poles). ✓ Explain why Earth is magnetic and how it affects compass needles. ✓ Describe one method of making an artificial magnet (stroking or electrical) with a diagram. ✓ Distinguish between permanent and temporary magnets (hard vs. soft iron). ✓ Draw magnetic field lines correctly for N–S arrangement, N–N arrangement, and single magnet. ✓ Explain why soft iron is used for electromagnet cores and hard iron for permanent magnets. ✓ Solve any word problem: e.g., 'A compass is placed at location X. The needle points northeast. What does this tell you about Earth's magnetic field direction at X?' If you hesitate on any item, revisit that section in your NCERT and the corresponding PYQ above. Confidence on exam day comes from repetition—solve each PYQ twice: once under timed pressure, once without time, carefully checking explanations and diagram details.