NIOS Class 12 Physics 312 solved practical File

NIOS Class 12 Physics 312 Solved Practical File (Lab Manual)

Get High Scores at the top of the heap in NIOS Physics Practicals by using the Ready-to-Use file from Unnati Education

It is risky to rush your practical record. Examiners check your file first, and internal marks are crucial. A clean, accurate, and current NIOS class 12 Physics 312 solved Practical File (Lab Manual) will protect your marks, reduce viva stress, and speed up evaluation for October 2025. This guide will tell you what you can expect from a NIOS Physics class 12 practical file that is up-to-date and follows the current norms.

NIOS Class 12 Physics 312 Practical Areas Covered

S. No.	Name of the Experiment	Page No.
1	To determine the internal diameter and depth of a cylindrical container (like a tin can, calorimeter) using vernier callipers and find its capacity. Verify the result using a graduated cylinder.	1
2	To determine the diameter of a given wire using a screw gauge.	20
3	To determine the radius of curvature of a concave mirror using a spherometer.	26
4	To find the period of a simple pendulum for small amplitudes and draw the graph of the length of the pendulum against the square of the period. Use the graph to find the length of the second pendulum.	30
5	To find the weight of a given body using the law of the parallelogram of vectors.	35
6	To study Newton's law of cooling by plotting a graph between cooling time and the temperature difference between the calorimeter and the surroundings.	39
7	To determine the specific heat of a solid using the method of mixtures.	44
8	To measure extensions in the length of a helical spring with increasing load. Find the spring constant from the spring extension graph.	49
9	To find the time required to empty a burette, filled with water, to ½, ¼, 1/8 of its volume, and so on. Plot a graph between volume and time and study the fractional rate of flow (analogy to radioactive decay).	53
Group B – Introduction
10	To determine the wavelength of sound produced (i) in an air column, (ii) the velocity of sound in air at room temperature, using a resonance column and a tuning fork.	57
11	To compare the frequencies of two tuning forks by finding the first and second resonance positions in a resonance tube.	62
12	To establish graphically the relation between the tension and length of a string of a sonometer vibrating in its fundamental mode, resonating with a given tuning fork. Use the graph to determine the mass per unit length of the string.	65
13	To find the value of v for different values of u in case of a concave mirror, and see its focal length (f) by plotting a graph between 1/u and 1/v.	77
14	To find the focal length (f) of a convex lens by plotting a graph between 1/u and 1/v.	82
15	To find the focal length of a convex mirror using a convex lens.	87
16	To determine the focal length of a concave lens by combining it with a suitable convex lens.	91
17	To draw a graph between the angle of incidence (i) and angle of deviation (D) for a glass prism and determine the refractive index of the glass using this graph.	96
18	To compare the refractive indices of two transparent liquids using a concave mirror and a single pin.	100
19	To set up an astronomical telescope and find its magnifying power.	105
Group C – Introduction
20	To verify the law of combination (series and parallel) of resistances using the ammeter–voltmeter method and coils of known resistances.	112
21	To compare the e.m.f.s. of two given primary cells using a potentiometer.	116
22	To determine the specific resistance of the material of two given wires using a metre bridge.	120
23	To determine the internal resistance of a primary cell using a potentiometer.	124
24	To determine the inductance and resistance of a given coil (inductor) using a suitable series resistance and an AC voltmeter.	135
25	To study the decay of current in an R.C. circuit while charging the capacitor using a galvanometer, and find the time constant of the circuit.	140
26	To draw the characteristic curve of a forward-biased PN junction diode and determine the static and dynamic resistance of the diode.	146
27	To draw the characteristics of an NPN transistor in the standard emitter mode. From the characteristics, find out (i) the current gain (β) and (ii) the voltage gain A_V with a load resistance of 1kΩ.	152
28	To draw the lines of force due to a bar magnet with (i) N-pole pointing north and (ii) N-pole pointing south. Locate the neutral points.	158
29	To determine the internal resistance of a moving coil galvanometer by the half deflection method, convert it into a voltmeter of a given range (e.g., 0–3V), and verify it.	163
Appendix – Answers to Check Your Understanding
	168

Download Solved Practical File

The NIOS Class 12 Physics 312 Solved Lab File (Lab Manual) is essential in this session

Most students don't realize how much the practical component can affect their final grade. Even if your theory is solid, a lack of precautions, poor observations, or a messy layout can affect your grade. A ready-to-use NIOS class 12 Physics 312 solved Practical File (Lab Manual) provides:

Every experiment requires a correct structure
Theoretical points that are concise and linked to formulas that you will actually use
Real numbers and observable tables for a better understanding of observation tables
Circuit sketches and ray diagrams with neat labels
One-line results with crisp cautions
Model answers and focused viva questions

Keep formatting consistent throughout. Use this master reference to write your observations in the places where your study centre asks you for live readings. You can use the NIOS Physics Practical File class 12 for internal linking without having to force them.

How the new Physics 312 practical file can help you score higher

Here is a walkthrough, starting with the concepts, of the main experiment groups that you will complete in the Class 12 Physics 312 Solved Practical File (Lab Manual). We explain what each experiment is for, what the examiner will be looking for, and how you can avoid common mistakes.

Group A: Measurements and mechanics

1) Verniers, screw gauges, and a sphereometer. Determine the internal diameter of thin wires, depth, and radius.
Use: To train accuracy, the use of least counts, and error handling.
Score cues: Write the least count clearly. Show zero error correction. Keep units consistent.
Common Loss: Writing the result without uncertainty. Add +- the least number where necessary.
2) Simple pendulum graph of T2 vs L
Purpose: Calculate the length of a pendulum by calculating the acceleration due to gravity.
Score cues: Small-amplitude, steady timing, straight-edge graph, and slope calculation shown.
Common Loss: Timing five oscillations only; use 20 or 30, and average.
3) Parallelograms of Forces
Use: Add vectors with real weights and check the graphical law.
Score cues: Draw neatly scaled vectors, mention triangle or parallelogram methods; compare theoretical values and experimental values.
4) Newton's Law of Cooling
Purpose: Time-temperature data, semi-log reasoning, and extracting the cooling rate.
Scoring cues: Record room temperature, keep constant surroundings, plot a clean curve, and comment on deviations.
Most common loss: Container material or temperature not noted.
5) Specific Heat by Method of Mixtures
Object: Energy Balance, heat loss equals heat gain.
Score cues: Make assumptions such as negligible heat losses, stirring gently, and recording a steady final temperature.
Most common loss: Forgetting to be pre-heated or dried.
6) Spring constant derived from
Object: Hooke's law with linear fit verification.
Scoring Cues: No error for rulers, hang masses slowly, plot load vs. extension, slope Clarity.
Common Loss: First reading at zero loading without removing slack.
7) Fractional Rate of Outflow Analogy
Purpose: A series of volume-time measurements to detect exponential behavior.
Score cues: Mark fractional level precisely, maintain a steady head and neat curve when interpreting.

Group B: Waves & optics

8) Tuning forks and a resonance column
Purpose: Wavelength & speed of sound in room temperature.
Score cues: Mention the end correction, record the temperature, and take the first-and resonance.
Common Loss: Ignoring the end correction completely
9) Sonometer basics
Purpose: Relationship between tension, length, and frequency; mass per length unit from slope.
Scoring Cues: Measure effective length between the bridges and show a graph.
10) The mirror and lens focal lengths via 1/u and 1/v
Purpose: Estimate f using the linearized lens/mirror equation.
Scoring Cues: Measure image position with parallax; do not label the axes.
11: Convex lenses and concave/convex combinations
Use: Combinations of focal length and lens to find virtual focal points.
Score cues: Sharp Image Criteria, Mount steady, Write sign convention in the theory line.
12) Prism deviation vs incidence
Use: Calculate the refractive index and minimum deviation by plotting D against i.
Score cues: Trace neatly using a fine pencil. Note the prism angle. Calculate m from D_min.
Common Loss: Skip normal alignment and add this step to the procedure
13: Refractive indices of liquids using concave mirrors and pins
Purpose: Realizes the apparent depth concept.
Score cues: Conduct in good lighting, take multiple readings, and show the formula used.
14: Astronomical telescope set-up and magnifying power
Goal: To understand customary adjustment and power equation f_o/f_e.
Score cues: Label the diagram clearly, mention the final image at infinity, and state the exit pupil briefly.

Group C: Electricity, magnetism, electronics

15: Series-parallel combinations
Use: Verify the equivalent resistance using the ammeter-voltmeter technique.
Scoring Cues: Record the least number of meters. If asked, plot V-I. Calculate R using slope.
Common Loss: Reverse series and parallel diagrams, keep them distinct.
16: Potentiometer Comparisons and Internal Resistance
Measure internal resistance and compare EMFs.
Score cues: Explain why a potentiometer over a voltmeter is preferred, maintain steady galvanometer measurements, and note balance length.
17) Metre Bridge for Specific Resistance
The purpose of the Wheatstone Principle is hands-on.
Score cues: Note temperature, measure wire length accurately, calculate r using units.
18: Inductance and resistance with AC Voltmeter
Purpose: Vector image of impedance with V, I.
Score cues: State the formula Z2 = (oL2)2; show how to isolate L.
19] RC charging time constant
Purpose: Exponential growth, t = RC.
Score cues: Use multiple points, semilog fit, or the 63 percent method to identify the t.
20) PN junction diode characteristics
I-V curve with forward bias, static, and dynamic resistance.
Scoring Cues: Axis Labels, Threshold Region Note, R_static = V/I in the point, r_d DV/DI along tangent.
21) NPN transistor in CE mode
Use: Input-output characteristics, current gain (b), small-signal voltage gains A_V, with given load.
Score cues: Mention the regions of operation. Read scales carefully. Show computations for b and a_V.
22. Magnetic field lines on a bar magnet
Use: Visualize the field pattern and neutral points.
Scoring Cues: Arrows N-S, symmetrical pattern. Mark neutral points with reason.
23: Galvanometer to voltmeter conversion
Calculate internal resistance using the half-deflection technique; design series resistance and verify.
Scoring Cues: Display formula R_s = V/I_g - G. Include neat circuit and the final check reading.

Examiners' rewards in 2025 will take a new format.

Use the same skeleton to guide all experiments in your NIOS Class 12 Physics 312 solved Practical File (Lab Manual).

Aim -- a single line of precision
Apparatus with measurement ranges where applicable
Theory- Two to four lines, including the formula key only
Procedure: numbered compact steps with alignment notes
Observations- Table with headings and units, the least number, and corrections
Calculations- a worked example followed by a summary line
Result with value and unit if applicable
Precautions: - Three to five points that are tied to the setup
Viva Prompts: Two or three questions that are likely to be asked with short answers

Keep margins neat, number your pages, and underline the headings. Here is a good NIOS Class 12 Physics Practical File.

Professional diagrams and data

Ray diagrams: Use a sharp pencil and fine arrows. The principal axis should be straight. Focus points must be marked correctly.
Circuit Diagrams: Standard Symbols, Battery Polarity Marked, Meters in Correct Positions, Ground Reference if Used.
Graphing: Select scales that cover most of the page. Mark at least 6-8 points. Draw the best-fit line. Write the slope calculation.
Tables, Headings in brackets, consistent significant numbers, and constants at the top.

Viva focus: short, exact answers examiners like

Potentiometers are preferred to compare EMFs
Because they use a null method, this means that no current is drawn out of the cell when it is balanced, and measurements are independent of internal resistance.
What is the end correction for the resonance column?
- The effective length is longer than the physical length because of an antinode in the tube. A constant correction is then added.
Why is a small amplitude required for the pendulum?
? - To maintain T independence from amplitude and ensure SHM approximation.
Meaning of the dynamic resistance diode:
The small-signal slope resistance r_d is equal to dV/dI, but not the V/I.
Conditions for minimum deviations in the prism:
Symmetric path, where the angle of incidence equals the angle of emergence.

Each line should be said in one or two sentences. This is enough, and you sound confident.

Students should stop worrying about Physics 312 and choose Unnati's Physics 312 files.

Syllabus - accurate content for 2025 October with refined formats
Use neat diagrams to make your presentation readable and reduce the need for rework
Realistic observation template to quickly take and fill out live readings
Bilingual option in Hindi or English
Typed or handwritten versions are available
Support for files and Viva questions on WhatsApp

This file will support your viva without any format arguments. This is what a NIOS Physics Practical File class 12 will do.

Submission discipline protects your results.

Keep a page that includes your name, enrollment code, session October 2025, and subject code 312.
Keep an index with page numbers.
Please leave a page for the certificate, space for your teacher's name, and comments from the examiner.
Use black or blue ink. One side is ruled to write text; the other blank page is for diagrams/graphs.
Please submit before the cut-off for your center to ensure that your marks are uploaded as soon as possible.
If you miss or fail to complete a practical, it can affect your SYCP and cause a delay.

Easy and fast ordering

Send a WhatsApp Message to 8800 777430 stating: Physics 312, Session, Medium, and Format choice.

Choose PDF to receive your hard copy immediately or PDF to receive it via courier.
Include your name and enrollment on the front page.
Orders can be delivered to India and abroad.
You can review your numbers and graphs quickly before you submit them.

Simple examples of precautions to earn easy marks

To avoid parallax when reading u and V, align the optical bench to eye level.
Handle the prisms only by their edges and keep the faces of your prisms clean.
When measuring sound speed or resistance, it is essential to note the room temperature.
Before changing circuit connections, turn off the power source.
Do not accept the first reading. Take multiple readings to get an average.

Smart checklist before you submit

Index matches page numbers
Each experiment is boxed by its results in units
The graphs are labeled with the axes, scale, and slope calculation
This experiment requires precautions
The Viva sheet is inserted at the end
Pages for signatures of teachers are left wherever needed

This one-page checklist will help you avoid the majority of penalties for reducing marks.

FAQs about NIOS Class 12 Physics 312 Solved Practical File (Lab manual)

Q1. What is in the NIOS Class Twelve Physics 312 Solved Practical File (Lab Manual )?
You will find all Physics 312 core experiments in a uniform form: goal, short theory, key formula, apparatus, step-by-step procedure, observation charts, graphs when required, clean diagrams and boxes, results, specific precautions, and a viva. It is aligned with the expectations for October 2025.

Q2. Is the file accepted by study centers across India and abroad?
The file is accepted by all study centers in India and abroad. The file structure is based on NIOS's standards for practical evaluation. Students in different regional centers have used this NIOS Class 12 Physics Practical File.

Q3. Is the file accepted by study centers across India and abroad?
You can get it in both Hindi and English. You can select either handwritten or typed. If your center prefers to keep manual records, handwritten files are neater and more examiner-friendly.

Q4. Can I use the observations that have been solved as a guide, or do I need to record new readings?
If your lab requires live readings, you can enter the actual values into the same tables. Then recalculate the results. You can follow the format and examples of calculations.

Q5. What happens if I miss the practical submission date?
If I miss the date for practical submission, my subject will be marked SYCP. My result could be delayed until the next cycle. It is best to complete the file at least one or two weeks prior to your center's deadline.

Final Note

You can focus on the theory if you finish a NIOS class 12 Physics 312 solved Practical File (Lab Manual) as early as possible. Keep your viva answers accurate and short. Use a clean, neat format. You can get a file that is ready-made and already meets the standards of October 2025 by sending it to +91 8800 774430. A solid record of practical experience now will save you stress in the future.