The NIOS Class 12 Physics Solved TMA is the one paper you can complete with the book open, the NIOS syllabus in front of you and zero exam pressure. It carries a 20 per cent weightage in your final Physics result, yet thousands of learners still hand it in casually and lose marks that were sitting there for the taking. On this page you get the complete Physics (312) Tutor Marked Assignment question paper for October 2026, two fully worked sample answers, the lesson references for every question and the exact presentation rules that decide whether an evaluator gives you 12 or 19 out of 20.
Reviewed by Rohit Sharma, Senior NIOS Counsellor. Written by Prateek Talwar, Founder, Unnati Educations.
Why the Physics 312 TMA Deserves Your Full Effort
The Tutor Marked Assignment is internal assessment. Your theory paper is written under a clock, with nerves, with one shot at a numerical you may have blanked on. The TMA has none of that. You have the NIOS Physics book, unlimited time and a defined set of questions.
That 20 per cent acts as a cushion. If mechanics or optics is not your strongest area, a strong TMA score protects your aggregate while you keep working on the theory paper. If your numericals are shaky, the TMA is where you can show clean, step-by-step working and earn credit for method rather than speed.
The trap is treating it as paperwork. Evaluators read hundreds of scripts, and an assignment that looks rushed, unlabelled or copied straight from a search engine reads as exactly that. The learners who score 18 and above are not smarter. They simply followed the instruction that was printed on the paper all along.
Read the Lesson Reference on Every Question
Look carefully at the October 2026 Physics TMA below. Every single question ends with a bracket that says (See Lesson – 8) or (See Lesson – 30) or (See Lesson – 13).
That bracket is not decoration. NIOS is telling you precisely which chapter of the official Physics study material the answer must come from. It does not say see a search engine. It does not say see an AI tool. It names a lesson.
Answers that use NIOS terminology, NIOS symbols and NIOS derivations match what the evaluator has been trained to award. Answers pulled from a generic source often use different notation, skip the SI unit or state a result the syllabus never covers. Open the lesson number written next to the question, then write. That single habit separates a 16 from a 9.
NIOS Class 12 Physics Solved TMA October 2026 Question Paper
This is the complete Physics (312) Tutor Marked Assignment for the October 2026 session, reproduced as issued. Maximum marks: 20. Attempt questions as directed.
Question 1. Answer any one of the following questions in about 40 to 60 words.
(a) In 1678, Robert Hooke discovered through experimentation that many solid materials exhibit a predictable relationship between applied force and the resulting deformation. This relationship, now known as Hooke’s Law, states: within the elastic limit, stress is directly proportional to the corresponding strain. This can be expressed mathematically as Stress = E × Strain, or E = Stress / Strain, where E is the constant of proportionality called the modulus of elasticity. Since there are different types of strain, can one modulus of elasticity explain all material behaviours under stress? Explain your answer by describing how each type of strain relates to a different modulus of elasticity. (See Lesson – 8)
(b) A steel ball is subjected to increasing pressure all around it. This pressure causes the ball to shrink slightly and develops stress inside it. The data showing normal stress developed inside the steel ball corresponding to the volumetric strain is tabulated below.
| Normal Stress (σ) in N/m² | Volumetric Strain (ΔV/V) | Ratio σ/(ΔV/V) in N/m² |
|---|---|---|
| 10 × 10⁶ | 62.5 × 10⁻⁶ | 160 × 10⁹ |
| 20 × 10⁶ | 125 × 10⁻⁶ | 160 × 10⁹ |
| 50 × 10⁶ | 312.5 × 10⁻⁶ | 160 × 10⁹ |
| 100 × 10⁶ | 625 × 10⁻⁶ | 160 × 10⁹ |
As can be seen from the table, normal stress and volumetric strain change simultaneously, but their ratio remains constant. Explain why this ratio remains unchanged. What is this constant called, and what is its SI unit? (See Lesson – 8)
Question 2. Answer any one of the following questions in about 40 to 60 words.
(a) Find the degree of freedom, Cp, Cv and total energy of a He molecule at 300 K temperature. (See Lesson – 10)
(b) An iron rod with a length of 40.0 cm and a diameter of 4.0 cm is shown in the given diagram. One end of the rod is in contact with a large reservoir of ice at its melting point, while the other end is in contact with a large reservoir of water at its boiling point. The rod is insulated along its surface, ensuring that heat transfer occurs only along its length. Given that the thermal conductivity of iron is 79 W m⁻¹ K⁻¹, determine the rate and direction of heat flow through the rod. (See Lesson – 12)
Question 3. Answer any one of the following questions in about 40 to 60 words.
(a) If the modulating signal in an AM system is given by Va = 5 sin 3140t and the frequency of the upper side band is 4.5 × 10⁵ Hz, find the angular frequency of the carrier wave. (See Lesson – 30)
(b) The communication capacity of visible light in an optical fibre is about 100,000 times greater than that of a typical microwave in a metallic conductor. Explain. (See Lesson – 30)
Question 4. Answer any one of the following questions in 100 to 150 words.
(a) Consider an oscillatory system consisting of two blocks of masses m₁ = 3 kg and m₂ = 2 kg, connected by a massless spring with a spring constant k = 200 N/m. The blocks are pulled apart with equal forces of magnitude F = 5 N each and then released. Calculate the angular frequency of each mass. Assume that the system moves on a smooth horizontal surface, and the centre of mass remains stationary. (See Lesson – 13)
(b) Conduct an experiment at home to study simple pendulum oscillations. Using a string (1 m) and a small weight (key, eraser or stone), set up a simple pendulum by fixing the string to a support and use a stopwatch to measure the time taken. Displace it slightly and release it. Measure the time for 10 oscillations, then calculate the time period T and hence acceleration due to gravity (g) using g = 4π²L / T². Repeat for different lengths (for example 50 cm and 1.5 m) and observe changes. Does mass affect T? How would T change on the Moon, where g on the Moon is one sixth of g on Earth? (See Lesson – 13)
Question 5. Answer any one of the following questions in 100 to 150 words.
(a) An object is placed at a distance of 6 cm from the first focus of a convex lens. The image is formed 24 cm away from the other focus.
(i) Find the focal length of the lens.
(ii) If the lens is made of glass with refractive index 1.5, calculate the radius of curvature of the lens surfaces (assume a bi-convex lens with equal radii).
(iii) If an object is placed 36 cm from the lens, find the image distance.
(iv) What will be the magnification of the image formed in the above case? Is the image real or virtual? (See Lesson – 20)
(b) An optical instrument made by using a large concave mirror is used to see distant stars and possesses large light-gathering power in order to obtain a bright image of even a faint star deep in space. Explain the construction and working of this device with a suitable ray diagram. Also describe why this device is better than an optical instrument which is used for the same function but uses a large convex lens. (See Lesson – 23)
Two Sample Answers from the Physics 312 TMA
Below are two model answers written in the style NIOS evaluators expect: formula first, symbols defined, substitution shown, unit stated, conclusion in one line. Study the structure as much as the content.
Sample Answer: Question 1(a), Modulus of Elasticity
No, a single modulus of elasticity cannot explain all material behaviour. Each type of strain has its own modulus. Linear strain relates to Young’s modulus, which describes resistance to a change in length. Volumetric strain relates to the bulk modulus, which measures resistance to a change in volume. Shearing strain relates to the modulus of rigidity, which explains resistance to a change in shape. Hence different moduli are required for different types of stress.
Why this scores well: it answers the question in the first sentence, names all three moduli with the strain each one belongs to, and stays inside the 40 to 60 word limit. It is drawn from Lesson 8, exactly as instructed.
Sample Answer: Question 3(a), Angular Frequency of the Carrier Wave
Given: Va = 5 sin 3140t, so the modulating angular frequency ωm = 3140 rad s⁻¹.
Step 1. Modulating frequency fm = ωm / 2π = 3140 / 6.28 = 500 Hz.
Step 2. For amplitude modulation, the upper side band frequency fUSB = fc + fm.
Step 3. Therefore fc = fUSB − fm = (4.5 × 10⁵) − 500 = 4.495 × 10⁵ Hz.
Step 4. Carrier angular frequency ωc = 2πfc = 2π × 4.495 × 10⁵ ≈ 2.82 × 10⁶ rad s⁻¹.
Why this scores well: every line is a separate step with the formula stated before the numbers. The evaluator can award method marks even if a single arithmetic slip creeps in. This is drawn from Lesson 30.
Want the remaining answers? Questions 1(b), 2(a), 2(b), 4(a), 4(b), 5(a), 5(b) and both project options in Question 6 are solved in full, with worked numericals and diagrams, in our complete Physics (312) solution set for October 2026. Message the NIOS desk on WhatsApp at 9654 279 279 to get it, or use 9899 436 384. Available in English medium and Hindi medium, as PDF or handwritten.
How to Write the NIOS Class 12 Physics Solved TMA for Full Marks
Rewrite in Your Own Handwriting and Your Own Words
Identical wording across submissions is the fastest way to lose credit. Use our solutions to understand the method, then rebuild the answer in your own sentences. Same physics, your voice. An answer that reads like a machine produced it invites suspicion; an answer that reads like a student who understood the lesson invites marks.
Draw the Diagram Even When It Is Not Demanded
Physics rewards visuals. A ray diagram for the reflecting telescope, a labelled sketch of the insulated iron rod between the two reservoirs, a projectile parabola with the angle marked. Draw the diagram in pencil, label it in black pen, and keep it clean. Diagrams communicate understanding in a way three paragraphs of prose cannot.
Follow the Formula, Symbols, Substitution, Unit Order
Every numerical answer should read in this sequence: state the formula, define each symbol, substitute the given values, arrive at the result with the correct SI unit, then close with a one-line conclusion. Look again at the Question 3(a) sample above. That structure is why it earns full credit.
Use Pencil for Tables and Black Pen for Headings
Rule your tables in pencil so the lines stay straight and can be corrected. Write headings and final answers in black or blue pen. Leave generous white space between answers. Number every question exactly as it appears on the paper. Presentation is not cosmetic; it is the first thing the evaluator sees.
Submit Before the Deadline
Late submissions are marked more strictly and, in some cases, are not accepted at all. Submit the completed assignment to your allotted study centre well before the last date announced by NIOS for the October 2026 session, and keep a photocopy or scan for your own records.
Mistakes That Quietly Cost Physics Marks
- Writing answers from a general web source instead of the NIOS lesson named on the paper.
- Skipping the SI unit at the end of a numerical. A number without a unit is an incomplete answer.
- Attempting every option when the paper clearly says answer any one.
- Ignoring word limits. A 40 to 60 word question does not need a page and a half.
- Handing in illegible handwriting. An answer that cannot be read cannot be marked.
- Leaving diagrams unlabelled. An unlabelled sketch earns very little.
Solve the Last Five Years of Question Papers Too
The NIOS TMA teaches you the syllabus; previous year question papers teach you the exam. Physics questions repeat in substance across sessions even when the format shifts between true or false, match the following and passage-based items. Working through five years of Physics (312) papers alongside your TMA is the single most reliable way to walk into the April 2027 theory paper without surprises. Practical file guidance and viva questions for Physics are also available through our NIOS desk.
Frequently Asked Questions
How many marks does the NIOS Class 12 Physics TMA carry?
The Tutor Marked Assignment carries 20 per cent weightage in your final Physics (312) result, and the assignment itself is set for 20 marks. Because it is internal assessment completed at home with the study material available, it is the most controllable component of your score. A strong TMA performance directly cushions your overall result if the theory paper does not go perfectly.
Are the October 2026 Physics TMA questions the same as the April session?
NIOS issues session-specific assignments, so you must complete the paper released for your own session. The October 2026 Physics (312) TMA reproduced on this page is the current one. Question themes such as elasticity, thermal conduction, oscillations, optics and communication recur across sessions, but the exact wording, data and lesson references change. Always work from the paper matching your admission session.
Can I write my TMA answers using AI or a search engine?
It is a poor strategy. Every question on the Physics TMA ends with a lesson reference such as See Lesson 8 or See Lesson 30, which tells you that NIOS expects the answer to come from its own study material. Generic sources often use different notation, omit SI units or cover content outside the syllabus. Use the NIOS book, then write in your own words.
Where can I get the complete Physics 312 solved TMA for October 2026?
Unnati Educations NIOS provides the full worked solution set for Physics (312), covering every question and both project options, with step-by-step numericals and diagrams. It is available in English medium and Hindi medium, as a PDF or as a handwritten assignment. Message the NIOS desk on WhatsApp at 9654 279 279 or 9899 436 384 to receive it.
Do diagrams really matter in a Physics assignment?
Yes. Questions on the reflecting telescope, the lens formula, the insulated iron rod and projectile motion all invite a labelled diagram, and several of them explicitly require a ray diagram. Draw in pencil, label in pen, and keep the figure uncluttered. A clear labelled diagram demonstrates understanding quickly and is far easier for an evaluator to award marks against than dense prose.
What happens if I submit my TMA late?
Late assignments are marked more strictly and may not be accepted after the cut-off announced by NIOS for the session. Submit the completed handwritten assignment to your allotted study centre before the last date, obtain an acknowledgement where possible, and retain a scan or photocopy. Do not leave the submission to the final week, as study centres often face a rush at that point.
Disclaimer
Unnati Educations is an independent academic support platform and is not affiliated with, endorsed by, or associated with the National Institute of Open Schooling (NIOS) or any government body. The question paper reproduced above is shown for reference and study purposes only. Learners should always confirm assignment details, submission dates and evaluation criteria on the official NIOS website at nios.ac.in.
