SPM Physics Amali: Electromagnetic Induction Explained

 

Electromagnetic Induction (Induced Current)

Apabila magnet bergerak relatif terhadap gegelung, arus teraruh dihasilkan dalam gegelung.

When a magnet moves relative to a coil, a current is induced in the coil.

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👀 Key Observations | Pemerhatian Penting

✅ Jarum galvanometer terpesong apabila magnet digerakkan masuk ke dalam gegelung.

✅ The galvanometer needle deflects when the magnet is moved into the coil.

✅ Jarum juga terpesong apabila magnet ditarik keluar dari gegelung.

✅ The needle also deflects when the magnet is pulled out of the coil.

✅ Tiada pesongan apabila magnet dan gegelung berada dalam keadaan pegun.

✅ No deflection occurs when both the magnet and coil remain stationary.

✅ Pesongan berlaku hanya apabila terdapat perubahan fluks magnet.

✅ Deflection occurs only when there is a change in magnetic flux.

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🔬 Physics Behind It | Prinsip Fizik

✅ Magnet yang bergerak menghasilkan perubahan medan magnet dalam gegelung.

✅ A moving magnet causes a changing magnetic field through the coil.

✅ Perubahan medan magnet menghasilkan arus teraruh.

✅ The changing magnetic field induces a current.

✅ Semakin cepat magnet digerakkan, semakin besar arus teraruh.

✅ The faster the magnet moves, the greater the induced current.

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❌ Common Mistakes

❌ Menganggap magnet perlu menyentuh gegelung untuk menghasilkan arus.

❌ Assuming the magnet must touch the coil to induce a current.

❌ Menganggap magnet pegun boleh menghasilkan arus teraruh.

❌ Assuming a stationary magnet can induce current.

❌ Mengelirukan elektromagnet dengan induksi elektromagnet.

❌ Confusing an electromagnet with electromagnetic induction.

❌ Tidak memerhatikan arah pesongan galvanometer.

❌ Ignoring the direction of galvanometer deflection.

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⚠️ Safety / Handling

⚠️ Gerakkan magnet secara perlahan dan terkawal.

⚠️ Move the magnet in a controlled manner.

⚠️ Elakkan menjatuhkan magnet atau galvanometer.

⚠️ Avoid dropping the magnet or galvanometer.

⚠️ Jangan menarik wayar sambungan dengan kuat.

⚠️ Do not pull the connecting wires forcefully.

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🎯 SPM Exam Tip

📌 Arus teraruh hanya wujud apabila terdapat perubahan fluks magnet.

📌 Induced current exists only when there is a change in magnetic flux.

📌 Semakin laju magnet digerakkan:

📌 The faster the magnet is moved:

✅ Semakin besar pesongan galvanometer.

✅ The greater the galvanometer deflection.

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📌 Menukar arah pergerakan magnet akan menukar arah arus teraruh.

📌 Reversing the direction of magnet movement reverses the induced current.

📌 Menukar kutub magnet yang memasuki gegelung juga menukar arah arus.

📌 Reversing the magnet pole entering the coil also reverses the induced current.

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🧠 SPM Concept Check

Observation

Jarum galvanometer terpesong apabila magnet digerakkan.

The galvanometer needle deflects when the magnet is moved.

Inference

Arus teraruh dihasilkan dalam gegelung.

An induced current is produced in the coil.

Conclusion

Perubahan medan magnet menghasilkan arus teraruh.

A changing magnetic field induces an electric current.

SPM Physics Amali: Current Flow in a Series Circuit

Litar siri hanya mempunyai satu laluan untuk arus mengalir. Oleh itu, arus adalah sama di setiap bahagian litar.

A series circuit has only one path for current flow. Therefore, the current is the same at every point in the circuit.

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👀 Key Observations | Pemerhatian Penting

✅ Ammeter menunjukkan bacaan yang sama walaupun diletakkan pada kedudukan yang berbeza dalam litar.

✅ The ammeter shows the same reading even when placed at different positions in the circuit.

✅ Hanya terdapat satu laluan untuk arus mengalir.

✅ There is only one path for current flow.

✅ Semua elektron mesti melalui setiap komponen dalam laluan yang sama.

✅ All electrons must pass through every component along the same path.

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❌ Common Mistakes

❌ Menganggap arus semakin berkurang selepas melalui mentol.

❌ Assuming the current decreases after passing through a bulb.

❌ Menganggap bacaan ammeter bergantung pada kedudukan ammeter dalam litar siri.

❌ Assuming the ammeter reading depends on its position in a series circuit.

❌ Mengelirukan litar siri dengan litar selari.

❌ Confusing a series circuit with a parallel circuit.

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⚠️ Safety / Handling

⚠️ Ammeter mesti disambung secara siri dengan litar.

⚠️ An ammeter must be connected in series with the circuit.

⚠️ Pastikan sambungan wayar kemas sebelum menghidupkan bekalan kuasa.

⚠️ Ensure all wire connections are secure before switching on the power supply.

⚠️ Matikan bekalan kuasa sebelum menukar kedudukan ammeter.

⚠️ Switch off the power supply before changing the ammeter position.

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🎯 SPM Exam Tip

📌 Dalam litar siri:

📌 In a series circuit:

I₁ = I₂ = I₃

✅ Arus adalah sama pada semua bahagian litar.

✅ Current is the same throughout the circuit.

📌 Jika ammeter dipindahkan ke mana-mana kedudukan dalam litar siri, bacaannya tetap sama.

📌 If the ammeter is moved to any position in a series circuit, the reading remains the same.

📌 Ini kerana hanya terdapat satu laluan untuk aliran cas.

📌 This is because there is only one path for charge flow.

Magnetic field lines around a straight conductor carrying current.

 

A magnetic compass shows the presence and direction of the magnetic field around a straight length of current-carrying wire.

The field direction can also be determined using The Right-Hand Grip Rule.

Griffin & George Limited-Slit Plate for Griffin Raybox

 

Polarisation of Light Using Polaroid Filters | SPM Physics Experiment

Penapis polaroid hanya membenarkan gelombang cahaya yang bergetar dalam satu satah untuk melaluinya.

A polaroid filter allows only light waves vibrating in one plane to pass through.

👀 Key Observations | Pemerhatian Penting

✅ Apabila kedua-dua polaroid selari, cahaya paling terang.

✅ When both polaroids are parallel, maximum light passes through.

✅ Apabila satu polaroid diputar, imej menjadi semakin gelap.

✅ When one polaroid is rotated, the image becomes dimmer.

✅ Pada sudut 90°, hampir tiada cahaya dapat melalui kedua-dua polaroid.

✅ At 90°, almost no light passes through both polaroids.

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🎯 SPM Exam Tip

📌 Polarisation membuktikan bahawa cahaya ialah gelombang melintang.

📌 Polarisation proves that light is a transverse wave.

📌 Gelombang membujur tidak boleh mengalami polarisasi.

📌 Longitudinal waves cannot be polarised.