Step marking in Class 12 Physics.

A five-mark numerical in Class 12 Physics is almost never five marks for the final number. It is a mark for the formula, a mark or two for substitution and rearrangement, a mark for the arithmetic, and a mark for the answer carrying its unit. A student who reaches the wrong number through the right physics keeps most of them — and a student who writes the right number with nothing above it frequently does not.

By Anant Khemka · 8 October 2026

Where the marks actually sit

The exact split belongs to the paper, and the board publishes a marking scheme for each one. But the shape repeats, and it is worth a Class 12 student knowing it:

The practical consequence is the thing students most often get wrong about Physics: showing your working is not politeness. Most of the marks are in the working.

A wrong final answer is usually not a zero

If a student uses the right relation, substitutes correctly, and then slips in the arithmetic, the steps before the slip still earn their marks — and if the wrong value is then used correctly through the rest of the question, those later steps earn theirs too. That is error carried forward, and in Physics it is where the single largest difference between a strict and a fair marker shows up.

The reverse also holds and surprises people. A correct final number with no working is not automatically full marks, because the marks for formula, substitution and working were never earned. Boards vary on how much they allow for this; a student should not rely on it.

Two things worth correcting, because they are widely taught

Students are routinely told that Physics deducts a mark for a missing unit and penalises wrong significant figures. We went looking for that in CBSE's published sample-paper marking schemes, 2019-20 through 2025-26, and could not find it.

• Units. The unit appears in the printed answer throughout — 4.9 m/s, 13.7 cm — but no scheme shows a separate mark for it, and none instructs a deduction for omitting it. That is not the same as saying it is safe to leave off; it means the published basis for the deduction is not there.
• Significant figures. No rule on digits or rounding appears anywhere. The schemes' own answers are not even internally consistent about precision, printing 0.2032 amu and 189.2808 MeV alongside 4.9 m/s.

Diagrams do carry marks, but as whole items — a circuit diagram worth one mark, a ray diagram worth two — rather than split between the drawing and its labels. One older sample scheme asks for a ray diagram “with proper labeling”, which is the closest thing to a labelling instruction we found.

None of this means your centre should stop expecting units. It means that if you deduct for one, you are applying a house convention rather than a published rule, and it is worth saying so to the class rather than letting them believe the board will do the same.

One slip is charged once

CBSE's general instruction to examiners — printed in the marking schemes it publishes on cbse.gov.in, and unchanged across them for over a decade — is explicit about this: “No marks to be deducted for the cumulative effect of an error. It should be penalized only once.” A student who takes a wrong value into four later steps loses the mark where the error happened, not at every step it touched. It is the clearest statement of the principle in any Indian board document, and it is the one teachers most often apply inconsistently under time pressure.

Why two teachers mark the same script differently

Because the split above is a convention applied by a person at the end of a long day. The common inconsistencies are predictable: whether a formula written only in its rearranged form earns the formula mark; whether the unit mark is deducted once per paper or once per question; whether a student who takes a different but valid route gets the step marks a scheme written around one route does not describe.

That last one is the hardest, and it is not solved by marking faster. A scheme that names a single derivation has nothing to award a student who took another valid one — one of a hundred and eleven things that make a handwritten paper difficult to mark consistently.

Common questions

Does CBSE give step marks in Physics?

Yes — CBSE publishes a marking scheme for each paper that allocates marks across the steps of an answer rather than to the final result alone, and examiners are instructed to award on it. The published scheme for your specific paper is the authority on the exact split; the shape in the table above is the pattern, not a rule.

Will I get marks if my final answer is wrong?

Usually some, if the working is there and the method is right. The steps completed correctly before the mistake still earn their marks, and a wrong value used consistently afterwards is normally followed through. You will not get the arithmetic mark or the final-answer mark. This is exactly why writing the working is worth more than writing neatly.

Do I lose marks for not writing the formula?

Often, yes — it is usually a separate mark. A student who goes straight from the given values to a substituted expression has done the physics but not shown the step the scheme pays for. Writing the relation first costs one line.

Is step marking the same in Maths?

Class 10 Maths is set out separately — including the figure being worth marks in its own right. Short version below.

The principle is the same; the split is shaped differently. In CBSE's published Class 10 Maths scheme the marks fall on forming the equation, reducing it to a solvable form, solving it, and choosing the valid root — there is no separate “state the formula” mark the way there often is in Physics. Where a figure is needed it is marked in its own right, between half a mark and two. What those schemes do not contain is any rule about units or significant figures, so do not assume a Physics habit transfers.

The subject where this matters most

Not Physics — Accountancy, where one wrong figure walks from the journal into the ledger, the trial balance and the balance sheet, and the marks are spread half a mark a line. How Class 12 Accountancy is marked, including the narration rule that quietly disappeared.