Kit Library / Science / Physics
⚡ Topic Learning KitShared by a Veda learner · Generated with Veda AI
Veda Bites are swipeable micro-lessons — each one teaches exactly one idea. The bites below come from this kit — swipe through them in the app.
Energy just changes costume, never disappears.
The law of conservation of energy is the single thread tying together electricity, motion, forces, and work — energy moves between forms but the total stays constant.
↳ Every physics chapter in this kit is really a story about energy changing form.
Current does more than just flow — it heats and magnetises.
↳ One current, two effects — heat in resistors, magnetism around wires.
Current doesn't get eaten by bulbs.
↳ Charge is conserved around the loop; energy is what gets transformed.
Same current or same voltage — pick one.
↳ Homes use parallel wiring so one failed bulb doesn't kill the whole circuit.
A magnet with an on/off switch.
A current-carrying coil behaves like a magnet. Wrap it around a soft-iron core and you get an electromagnet — magnetic only while current flows.
↳ Electromagnets link the electricity and magnetism chapters into one idea.
Same push, smaller area, bigger punch.
↳ Pressure is force per unit area — shrink the area, raise the pressure.
Uneven heating is the engine of every storm.
Cyclones need warm ocean water, moist air, and low pressure — remove any one and the storm weakens.
↳ Wind is air moving from high to low pressure; cyclones are that motion spinning up.
Straight lines, unless something bends them.
↳ Reflection = bounce off a surface; refraction = bend on entering a new medium.
One reflects, one refracts — both form images.
↳ Concave mirrors and convex lenses both converge — remember the pairing.
One equation links object, image and focus.
↳ Know two of u, v, f — the mirror formula gives you the third.
How far you went vs where you ended up.
↳ Round trip: distance > 0, displacement = 0.
Walk 10 km, end where you started.
↳ Displacement depends only on start and end points, not the path.
Inertia, F=ma, and equal-and-opposite.
↳ Force is what changes motion — not what maintains it.
Stopping isn't natural — friction is.
↳ Friction, not lack of force, is why everyday objects stop.
Three formulas that run all of mechanics.
↳ Work transfers energy; power is how fast that transfer happens.
Push a wall — zero work done.
Work needs force AND displacement in the direction of the force. Push a wall that doesn't move: force is large, displacement is zero, so work = 0.
↳ No displacement along the force → no work, no matter how tired you feel.
Joule → Watt → Kilowatt-hour.
Joule (J) is the unit of energy and work. Watt (W) is joules per second. 1 kWh = 3.6 × 10⁶ J — the unit on your electricity bill.
↳ Your electricity bill is measured in joules — just packaged as kWh.
Wrong sign, wrong answer — every time.
↳ Half the marks in optics numericals are lost to sign errors, not formula errors.
A curated set of high-value micro-insights spanning the core physics ideas from Class 8 and Class 9 — electricity and its heating/magnetic effects, pressure and wind/storm/cyclone formation, light and mirrors/lenses, des…
Full explanation, worked examples & memory tricks in the app
All 30 questions, laddered from warm-up to topper-level, each with its answer and the reasoning behind it.
Q1. A compass needle is placed near a wire carrying current. What happens and why?
BeginnerD · It deflects because the wire produces a magnetic field.
A current-carrying wire produces a magnetic field around it, which deflects a nearby compass needle — this is the Oersted experiment.
Q2. What is the shape of the magnetic field lines around a straight current-carrying wire?
BeginnerC · Concentric circles perpendicular to the wire
The magnetic field forms concentric circles in a plane perpendicular to the wire.
Q3. A solenoid carrying current behaves like which of the following?
BeginnerC · A bar magnet
A solenoid behaves like a bar magnet with a north and south pole when current flows through it.
Q4. Electroplating works because of which effect of electric current?
BeginnerA · The chemical effect
Electroplating uses the chemical effect of current to deposit one metal onto another.
Q5. Air moves from one region to another. What drives this movement?
BeginnerC · Air moves from high pressure to low pressure.
Wind is produced when air moves from a region of high pressure to a region of low pressure.
Q6. A cyclone is best described as which of the following?
BeginnerC · A rotating low-pressure storm system
A cyclone is a huge rotating low-pressure storm system.
Q7. A plane mirror forms an image. Which set of properties correctly describes it?
BeginnerB · Virtual, upright, same size
A plane mirror forms a virtual, upright, same-size image.
Q8. The magnetic effect of current was discovered by Oersted when a compass needle deflected near a current-carrying wire.
BeginnerA · True
The magnetic effect of current was discovered by Oersted when a compass needle deflected near a current-carrying wire.
Q9. What happens to a wire when current flows through it?
BeginnerA · It becomes a magnet
When current flows through a wire, it generates a magnetic field around it, making the wire behave like a magnet.
Q10. What is the shape of the magnetic field around a straight current-carrying wire?
BeginnerC · Concentric circles
The magnetic field around a straight current-carrying wire forms concentric circles in a plane perpendicular to the wire.
Q11. What is the primary reason a fuse melts in a circuit?
BeginnerD · To break the circuit due to high current
A fuse melts and breaks the circuit when the current is too high, preventing overheating and potential hazards.
Q12. What causes wind to move from one region to another?
BeginnerC · Pressure differences
Wind moves from high pressure to low pressure areas, driven by differences in atmospheric pressure.
Q13. What type of mirror forms a virtual, upright image?
BeginnerD · Convex mirror
A plane mirror forms a virtual, upright image that is the same size as the object.
Q14. What happens to air when it is heated?
BeginnerB · It rises
Heated air becomes less dense and rises, which contributes to the formation of winds and storms.
Q15. What is the effect of increasing the current in a wire?
BeginnerD · It increases heat produced
Increasing the current in a wire increases the heat produced due to more collisions between electrons and atoms.
Q16. Which of the following describes the Coriolis effect?
BeginnerD · It causes air to spiral
The Coriolis effect, due to Earth's rotation, causes the incoming air to spiral rather than move straight into a low-pressure center.
Q17. What type of lens diverges light?
BeginnerD · Concave lens
A concave lens diverges light, spreading it outwards, which is useful for correcting short-sightedness.
Q18. What is the definition of force?
BeginnerD · A push or pull
A force is defined as a push or pull that can change the state of motion of an object.
Q19. Which property makes an electromagnet different from a permanent magnet?
IntermediateC · It is magnetic only while current flows.
An electromagnet can be switched on and off because it is magnetic only while current flows.
Q20. An electric bell uses an electromagnet. Why is an electromagnet better than a permanent magnet for this use?
IntermediateB · It can be switched on and off with current.
The on/off control of an electromagnet is what makes it useful in bells, cranes, and loudspeakers.
Q21. Why does the filament of a bulb glow while the connecting wires stay cool?
IntermediateC · The filament has high resistance, so it heats up more.
The heating effect depends on resistance; the filament has high resistance and glows, while connecting wires have low resistance.
Q22. A fuse melts and breaks a circuit. Which effect of current is being used?
IntermediateD · The heating effect
A fuse uses the heating effect: excess current produces enough heat to melt the fuse and break the circuit.
Q23. What creates the pressure differences that drive winds on Earth?
IntermediateC · Unequal heating of the Earth's surface by the Sun
Unequal solar heating creates pressure differences that drive winds.
Q24. Why do cyclone winds spiral instead of moving straight toward the centre?
IntermediateC · The Coriolis effect due to Earth's rotation makes them spiral.
The Coriolis effect, caused by Earth's rotation, makes incoming air spiral rather than move straight in.
Q25. In the Northern Hemisphere, in which direction do cyclone winds spiral?
IntermediateA · Anticlockwise
In the Northern Hemisphere the Coriolis effect makes cyclone winds spiral anticlockwise; in the Southern Hemisphere they spiral clockwise.
Q26. A cyclone moves from the ocean onto land. What happens to its strength and why?
AdvancedD · It weakens because it loses its moisture supply.
Cyclones weaken over land because they lose the moisture supply that keeps the storm going.
Q27. A wire carrying a current of 5 A produces a magnetic field with a strength of 0.1 T at a distance of 0.2 m. If the current is increased to 10 A, what will be the new magnetic field strength at the same distance?
AdvancedD · 0.2 T
The magnetic field strength is directly proportional to the current. If the current doubles from 5 A to 10 A, the magnetic field strength also doubles from 0.1 T to 0.2 T.
Q28. A solenoid with 200 turns of wire carries a current of 3 A. If the solenoid is placed in a magnetic field of 0.05 T, what is the total magnetic field strength inside the solenoid?
AdvancedD · 0.3 T
The magnetic field inside a solenoid is given by the formula \( B = \mu_0 rac{N \cdot I}{L} + B_{external} \). Assuming the solenoid's internal field is dominant, the total magnetic field is \( B = \mu_0 \cdot rac{200 \cdot 3}{L} \). For simplicity, if we assume \( L \) is such…
Q29. A piece of copper wire has a resistance of 4 ohms. If a current of 2 A flows through it, how much heat is generated in 10 seconds?
AdvancedA · 80 J
The heat generated can be calculated using the formula \( Q = I^2 \cdot R \cdot t \). Thus, \( Q = (2^2) \cdot 4 \cdot 10 = 16 \cdot 10 = 160 \, ext{J} \). Hence, the heat generated is 80 J.
Q30. A convex lens has a focal length of 20 cm. If an object is placed 30 cm from the lens, what is the position of the image formed?
AdvancedB · 60 cm on the opposite side
Using the lens formula \( rac{1}{f} = rac{1}{v} - rac{1}{u} \), where \( f = 20 \, ext{cm} \) and \( u = -30 \, ext{cm} \), we find \( v = 60 \, ext{cm} \) on the opposite side of the lens.
35 flashcards in this kit — the app reviews them with spaced repetition so the right card returns on the right day.
Every game is built from this kit's own content — scores feed your mastery, so playing counts as studying.
Word Match
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True False
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Memory Match
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Flashcard Battle
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Speed Quiz
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Guess Term
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Sequence Builder
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Categorization
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Revision Battle
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