Light - reflection and refraction
Spherical mirrors, the mirror formula and magnification, refraction through a glass slab, lenses, the lens formula and power. Sign convention is where most of the arithmetic goes wrong.
Class 10 · Physics
Class 10 Physics tuition: ray diagrams and the numerical chain
Class 10 Physics covers light - reflection and refraction, the human eye and the colourful world, electricity, and the magnetic effects of electric current. In CBSE these are units within one Science paper rather than a separate subject. Two things carry most of the marks: ray diagrams, which are drawn rather than written, and multi-step numericals in electricity.
The physics units of Class 10 are unusual in the board paper because so much of the credit is not prose. A ray diagram earns marks for the arrows, the labels and the position of the image - a beautiful drawing without arrows scores badly. Electricity is the opposite problem: long numerical chains where an error in the second line survives to the last, and a child who cannot check their own work loses everything downstream of it.
A free 20-minute assessment. We find where your child actually is, then tell you what we would do about it. No card, no commitment.
What is taught
The Class 10 Physics syllabus, topic by topic
The human eye and the colourful world
Accommodation, defects of vision and their correction, dispersion through a prism, atmospheric refraction and scattering - why the sky is blue and the setting sun red.
Electricity
Current, potential difference, Ohm's law, resistance and resistivity, series and parallel combinations, and heating effect with power. The most numerical-heavy chapter in the course.
Magnetic effects of electric current
Magnetic field and field lines, field due to a current-carrying conductor and solenoid, force on a conductor, Fleming's rules, electromagnetic induction and the domestic circuit.
Class 10 Physics in detail
Why do ray diagrams lose so many marks?
Because they are marked as answers, not as drawings. The credit is in the arrows showing direction, the labelled focus and centre of curvature, and the image drawn in the right place with the right nature. A neat diagram missing arrows scores a fraction of a rough one that has them.
Children treat a ray diagram as illustration and examiners treat it as working. That mismatch is worth a great many marks across a board paper, and it is entirely fixable, because the requirements are short and fixed: two standard rays, arrows on every ray, focus and centre marked, image drawn and its nature stated.
We teach it as a checklist that gets applied every single time, including in rough work, until it is automatic. The point is not neatness - it is that each of those items has a mark attached to it.
How should a Class 10 electricity numerical be set out?
Given quantities first, then the formula, then the substitution, then the answer with its unit. In multi-step problems each stage gets its own line, so an error is contained rather than carried. Substituting the final answer back is the fastest way to catch a slip before the paper is handed in.
Electricity is where the physics units are won or lost, because the questions are long. A child who works in their head to save time loses the method marks and cannot find their own mistake afterwards, so a single slip in line two costs everything after it.
Writing each stage down looks slower and is not, because the checking is faster. It is the same discipline the Class 9 numericals should have built, which is why a child who skipped that habit meets it again here under board pressure.
Should we get help for physics alone?
Only if physics is genuinely the weak strand. Class 10 CBSE sets one Science paper covering all three, so marks lost in chemistry cannot be recovered by being strong in physics. The assessment tells you which strand is actually costing marks before anyone commits to a plan.
Parents usually name a strand because that is where the child says they are struggling, and children are not always right about that. Quite often the reported problem is physics numericals and the actual problem is that equations are not being balanced in chemistry - the same paper, a different chapter, and a much bigger loss.
So we assess the whole paper first and then say plainly where the hour is best spent. If the answer is that your child does not need physics help, we will say that. The full subject is on the Class 10 Science page.
At a glance
Class 10 Physics, topic by topic
What the year covers, and what a child on track can do by the end of it.
| Topic | What it actually involves |
|---|---|
| Light - reflection and refraction | Spherical mirrors, the mirror formula and magnification, refraction through a glass slab, lenses, the lens formula and power. Sign convention is where most of the arithmetic goes wrong. |
| The human eye and the colourful world | Accommodation, defects of vision and their correction, dispersion through a prism, atmospheric refraction and scattering - why the sky is blue and the setting sun red. |
| Electricity | Current, potential difference, Ohm's law, resistance and resistivity, series and parallel combinations, and heating effect with power. The most numerical-heavy chapter in the course. |
| Magnetic effects of electric current | Magnetic field and field lines, field due to a current-carrying conductor and solenoid, force on a conductor, Fleming's rules, electromagnetic induction and the domestic circuit. |
On track by the end of Class 10 looks like
- Draws a ray diagram with arrows, labels and a correctly placed image, not merely a neat sketch
- Applies the sign convention consistently in the mirror and lens formulae
- Works a multi-step electricity numerical and checks it by substituting back
- Uses Fleming's left- and right-hand rules without confusing which applies
- Explains a defect of vision and its correction in terms of where the image forms
Where it usually goes wrong
- Ray diagrams drawn without arrows, which score a fraction of the marks
- Sign convention applied inconsistently, so a correct method gives a wrong sign
- Series and parallel formulae swapped under exam pressure
- One early slip in a numerical chain carrying through to every later line
- Confusing Fleming's left-hand rule with the right-hand rule
Fees
What Class 10 Physics tuition costs
What Class 10 tuition costs
Class 10 sits in Class 9 and 10. Board-exam teaching, with past papers and marking schemes.
- Spoken English8 live classes/month
- ₹2,000/month
- All Subjects16 live classes/month
- ₹5,000/month
- One-to-One12 live classes/month
- ₹8,000/month
Per child, per month. See every plan and what is included.
Where this comes from
Sources for what is on this page
Everything above about the syllabus is checked against the boards’ own material rather than against other tuition sites. If a claim cannot be traced back to one of these, it is not on the page.
Same class
Everything else we teach in Class 10
Questions
Class 10 Physics, answered
Is physics a separate paper in Class 10 CBSE?
No. Physics, chemistry and biology share a single Science paper up to Class 10 and become separate subjects in Class 11. Some ICSE and international schools separate them earlier, so check with your child's school.
My child draws neat ray diagrams and still loses marks. Why?
Almost certainly missing arrows, or an unlabelled focus and centre of curvature, or the image not drawn where it actually forms. Ray diagrams are marked as working rather than as illustration, and each of those items carries its own mark.
Which Class 10 physics chapter is hardest?
Electricity for most children, because the numericals are long and an early error carries through the whole answer. The fix is setting the work out line by line so mistakes stay contained and can be found.
How much of the Class 10 Science paper is physics?
Roughly a third, alongside chemistry and biology, though the exact weighting is set each year. Check the current sample paper and syllabus on the CBSE Academic site rather than relying on last year's split.
How much of the Class 10 Science paper is physics?
Roughly a third, alongside chemistry and biology, though the exact weighting is set each year. Check the current sample paper on the CBSE Academic site rather than relying on last year's split.
My child draws neat ray diagrams and still loses marks. Why?
Almost certainly missing arrows, an unlabelled focus or centre of curvature, or the image not drawn where it actually forms. Ray diagrams are marked as working rather than as illustration, and each of those carries its own mark.
Which chapter should we start with if time is short?
Electricity. It carries the most numericals, the questions are long, and a single early slip propagates through an entire answer - so it is where a fortnight of disciplined setting-out moves the most marks.
Is it worth learning derivations?
For the ones the syllabus names, yes, because they are asked directly. But a derivation reproduced without understanding fails the moment the question changes a single condition, which is exactly what boards do.
How do I help if I do not know physics?
Read the answers, not the working, and check every number carries a unit. Then ask what the arrows on a ray diagram mean. Both find real lost marks and need no physics from you.
Does Class 10 physics matter for Class 11?
A great deal if your child takes science. Class 11 assumes the sign convention, the formula-substitution habit and comfort with numericals are already automatic, and it moves far faster than Class 10 did.
100% free · no card
See how your child is doing in Class 10 Physics.
A free 20-minute assessment. We find where your child actually is, then tell you what we would do about it. No card, no commitment.
- You tell us the class, board and what is going wrong.
- We match a teacher who has taught exactly that, and send you a time.
- A free 20-minute assessment. Sit beside your child if you like.
- No card, no commitment
- Live classes, never a crowd
- The same teacher every week