BPHCT 137 Solved Guess Paper 2026 for IGNOU Waves and Optics, prepared for B.Sc. General (BSCG) and B.Sc. Multidisciplinary (BSCM, FYUP) learners sitting the June 2026 or December 2026 Term-End Examination. Fifteen high-probability questions from Blocks 1 and 2, each solved in full from the IGNOU study material, chosen after reading four past papers line by line. Five complete answers are below; the full 19-page PDF is sent on WhatsApp at 9899436384.
BPHCT-137 Waves and Optics at a Glance
Key facts for IGNOU BPHCT-137 Waves and Optics and the 2026 solved guess paper file
- Course code: BPHCT-137
- Course title: Waves and Optics
- Programme: B.Sc. General (BSCG) and B.Sc. Multidisciplinary under FYUP (BSCM)
- Category: Discipline Specific Core (DSC), Physics, School of Sciences
- Credits: 4
- Blocks and units: 4 blocks, 14 units
- Paired laboratory course: BPHCL-138 Waves and Optics: Laboratory
- Term-End Exam duration: 2 hours
- Maximum marks: 50
- Paper rule: Five questions of 10 marks, all compulsory, internal choice inside each
- Questions in our file: 15 solved questions across 19 pages
- Coverage: Block 1 and Block 2 only (Units 1 to 8)
- Sessions analysed: 4 papers: June 2023, December 2024, June 2025, December 2025
- Target sessions: June 2026 and December 2026
- Delivery: PDF on WhatsApp: 9899436384
About the BPHCT 137 Solved Guess Paper for 2026
The BPHCT-137 solved file is a 19-page PDF holding 15 questions from Blocks 1 and 2 of Waves and Optics, each answered in full with every formula line, derivation step and labelled conclusion the Term-End examiner looks for. It is aimed at the June 2026 and December 2026 sessions.
Waves and Optics punishes a particular habit. Students memorise the final formula, write it down, and lose the four marks sitting in the derivation above it. Fringe width, Brewster's law, Laplace's correction and the Newton's rings radius relation are all cheap marks if the working is visible and expensive marks if it is not. Every answer in this file is written with that working left in.
Students collecting materials across several course codes in one session can browse our wider IGNOU Solved Guess Paper library, which is built to the same solving standard as this Waves and Optics file.
Sample Questions with Solutions from the BPHCT-137 Guess Paper
Five of the 15 solved questions are reproduced below in full, drawn from five different units, so the sample shows the real answer depth rather than the easiest items. Two are 10-mark answers and three are 5-mark answers, matching the mix in the actual paper.
Huygens Principle and Properties of Wavefronts
Question: State Huygens principle. Explain what is meant by a wavefront and write down the properties of wavefronts.
Huygens principle: every point on a wavefront acts as a source of secondary spherical wavelets, which spread forward at the same speed as the wave itself. After a given interval, the forward envelope, that is the common tangent to these secondary wavelets, forms the new position of the wavefront.
Wavefront: a wavefront is the locus of all points in a medium that are vibrating in the same phase at a given instant. The direction of propagation of the wave is always normal to the wavefront.
Properties of wavefronts:
- All points lying on a single wavefront are in the same phase of vibration.
- A wavefront is always perpendicular to the direction of wave propagation.
- Two wavefronts can never intersect each other.
- The shape of a wavefront depends on the source, and may be spherical, cylindrical or plane.
- In a homogeneous medium, all parts of a wavefront travel with the same speed.
Huygens principle therefore explains wave propagation by constructing each new wavefront from the secondary wavelets of the previous one.
Speed of Sound, Newton's Formula and Laplace's Correction
Question: Write the expression for the speed of sound in air proposed by Newton. Point out the discrepancy in this formula and explain how Laplace corrected it.
Newton's formula: Newton assumed that the compressions and rarefactions accompanying a sound wave in air occur isothermally, so the bulk modulus of air equals its pressure P. This gives v = √(P/ρ), where ρ is the density of air.
The discrepancy: at 0 degrees Celsius Newton's formula returns roughly 280 m s-1, whereas the measured speed of sound in air is close to 332 m s-1. Newton's value is short of the experimental result by about 16 per cent, far too large a gap to be explained by measurement error.
Laplace's correction: Laplace pointed out that sound propagates so rapidly that heat has no time to flow between compressed and rarefied regions. The compressions and rarefactions are therefore adiabatic, not isothermal, and the effective bulk modulus becomes K = γP.
The corrected expression is v = √(γP/ρ), where γ = CP/CV. Taking γ = 1.4 for air gives v close to 332 m s-1, in agreement with experiment.
Malus's Law and Brewster's Law
Question: (a) State Malus's law and explain how it is used to test an ideal polariser. (b) Discuss polarisation by reflection and derive Brewster's law.
(a) Malus's law: when plane-polarised light passes through an analyser, the intensity I of the transmitted light is proportional to the square of the cosine of the angle θ between the transmission axes of the polariser and the analyser, so I = I0 cos² θ, where I0 is the maximum transmitted intensity.
Testing an ideal polariser: place two polarisers one behind the other in the path of the light and rotate the second one. When the transmission axes are parallel, θ = 0 degrees and I = I0. When the axes are perpendicular, θ = 90 degrees and I = 0. Complete extinction at 90 degrees confirms ideal behaviour.
(b) Polarisation by reflection: when unpolarised light strikes a transparent surface, the reflected beam becomes partially polarised. At one particular angle of incidence, the polarising angle or Brewster angle ip, the reflected light is completely plane-polarised.
At this angle the reflected and refracted rays are mutually perpendicular, so ip + r = 90 degrees, giving r = 90 degrees - ip.
Applying Snell's law, μ = sin ip / sin r = sin ip / sin(90 degrees - ip) = sin ip / cos ip.
Hence μ = tan ip, which is Brewster's law: the refractive index of a medium equals the tangent of its polarising angle.
Young's Double-Slit Experiment and Fringe Width
Question: Describe Young's double-slit experiment. Obtain the conditions for bright and dark fringes and derive an expression for the fringe width.
Answer: Monochromatic light from a single source falls on two narrow, closely spaced slits S1 and S2. These act as coherent sources and produce alternate bright and dark interference fringes on a screen placed at a distance D.
Let d be the slit separation and y the distance of a point P from the central maximum. For D much greater than d, the path difference is Δ = dy/D.
Bright fringes: constructive interference requires Δ = nλ, so dy/D = nλ and yn = nλD/d, with n = 0, 1, 2, and so on.
Dark fringes: destructive interference requires Δ = (n + ½)λ, giving yn = (n + ½)λD/d.
Fringe width: the separation between two consecutive bright or dark fringes is β = yn+1 - yn = λD/d. Fringe width is therefore directly proportional to the wavelength and to the screen distance, and inversely proportional to the slit separation.
Newton's Rings
Question: Explain the formation of Newton's rings. Show that the radii of the dark rings are proportional to the square root of the natural numbers.
Formation: Newton's rings are concentric circular interference fringes formed when a plano-convex lens rests on a plane glass plate. The gap between them is a thin air film whose thickness increases outward from the point of contact. Light reflected from the upper and lower surfaces of this film interferes, producing alternate bright and dark rings.
Derivation: let R be the radius of curvature of the lens, rn the radius of the nth dark ring and t the air film thickness at that radius. From the geometry of the lens, rn² = 2Rt.
For dark rings in reflected light, 2t = nλ, so t = nλ/2.
Substituting, rn² = 2R(nλ/2) = nλR, and therefore rn = √(nλR).
Since λ and R are fixed for a given arrangement, rn is proportional to √n. The dark ring radii therefore follow the square roots of the natural numbers 1, 2, 3 and so on, which is why the rings crowd together as you move outward.
These five are complete answers rather than extracts. The remaining 10 come with the complete 19-page PDF on WhatsApp 9899436384.
WhatsApp 9899436384 for the BPHCT-137 solved fileTo see how closely the phrasing tracks the real examination, compare them against any IGNOU Previous Year Question Paper for this course code.
The same layout standard runs across our BSCG guess Paper range, which matters if you are sitting three or four science papers in one session and want your revision files to look and read the same way.
BPHCT-137 Waves and Optics Block and Unit Index
BPHCT-137 is a four-credit course built from four blocks holding 14 units, published in two volumes on eGyanKosh. The table below names every unit, lists the concepts actually examined from it, and shows which of them this guess paper reaches.
Unit numbering runs continuously from 1 to 14 rather than restarting in each block, which is worth knowing when you are matching a question to a book. Volume 1 holds Blocks 1 and 2, and Volume 2 holds Blocks 3 and 4, as listed on eGyanKosh, the official IGNOU repository.
| Block | Unit | Unit title | Concepts examined from this unit | In our file |
|---|---|---|---|---|
| Block 1: Waves, An Introduction | 1 | Wave Motion | One-dimensional wave equation, energy and power transported by a wave, wave groups and group velocity | Not covered |
| Block 1: Waves, An Introduction | 2 | Superposition of Waves | Standing waves on a string, nodes and antinodes, normal modes, harmonics, beats, resultant intensity of two superposed waves | Q3 and Q10 solved |
| Block 1: Waves, An Introduction | 3 | Acoustic Waves | Newton's formula and Laplace's correction, intensity and decibel level, reverberation and Sabine's formula, Doppler effect for sound | Q4, Q5 and Q6 solved |
| Block 1: Waves, An Introduction | 4 | Electromagnetic Waves | Maxwell's equations in free space, EM wave equation, transverse nature of EM waves, Huygens principle and wavefronts | Q1 and Q2 solved |
| Block 1: Waves, An Introduction | 5 | Polarisation of Light | Simple states of polarised light, Malus's law, Brewster's law, double refraction in calcite, Nicol prism, wave plates | Q7, Q8 and Q9 solved |
| Block 2: Interference | 6 | Interference by Division of Wave Front | Young's double-slit experiment, fringe width, Fresnel's biprism, Lloyd's mirror, displacement of fringes by a thin sheet | Q11 and Q12 solved |
| Block 2: Interference | 7 | Interference by Division of Amplitude | Thin film interference by reflection, Stokes' treatment, wedge-shaped films, Newton's rings and the ring radius relation | Q13 and Q14 solved |
| Block 2: Interference | 8 | Michelson Interferometer | Construction and working, circular and straight fringes, wavelength measurement, separation of a spectral doublet | Q15 solved |
| Block 3: Diffraction | 9 | Fresnel Diffraction | Fresnel half-period zones, zone plate and its focal lengths, diffraction at a straight edge and a circular aperture | Not covered |
| Block 3: Diffraction | 10 | Fraunhofer Diffraction | Single slit diffraction and intensity distribution, double slit diffraction, missing orders, resolving power | Not covered |
| Block 3: Diffraction | 11 | Diffraction Grating | Grating element and grating equation, principal maxima, angular half-width, dispersive power and resolving power of a grating | Not covered |
| Block 4: Lasers and Optical Fibre | 12 | Physics of Lasers | Spontaneous emission, absorption and stimulated emission, Einstein coefficients, population inversion, pumping and optical resonators | Not covered |
| Block 4: Lasers and Optical Fibre | 13 | Properties and Applications of Lasers | Directionality, monochromaticity, coherence length, speckle pattern, holography, industrial and medical applications | Not covered |
| Block 4: Lasers and Optical Fibre | 14 | Fibre Optics | Total internal reflection in a fibre, critical angle, numerical aperture, acceptance angle, step index and graded index fibres, attenuation | Not covered |
If you want to read the source units before attempting the guess paper, our unit-wise BPHCT 137 Study Material page lists all fourteen units in the same order as this table.
All 15 Questions Covered in the BPHCT-137 Guess Paper
The file holds 15 questions, five shown in full above and ten supplied on request. The list names each one, so nothing about what you are asking for is left to guesswork.
| No. | Question topic | Block and unit | Marks | Status on this page |
|---|---|---|---|---|
| 1 | Huygens principle, wavefronts and their properties | Block 1, Unit 4 | 5 | Shown above |
| 2 | Maxwell's equations in free space and the transverse nature of EM waves | Block 1, Unit 4 | 5 | In full file |
| 3 | Standing waves on a string, fundamental frequency and normal modes | Block 1, Unit 2 | 5 | In full file |
| 4 | Speed of sound in air, Newton's formula and Laplace's correction | Block 1, Unit 3 | 5 | Shown above |
| 5 | Reverberation, Sabine's formula and seven acoustic defects with remedies | Block 1, Unit 3 | 10 | In full file |
| 6 | Doppler effect for sound, moving listener and moving source cases | Block 1, Unit 3 | 5 | In full file |
| 7 | Polarisation of light and the three simple states of polarised light | Block 1, Unit 5 | 5 | In full file |
| 8 | Malus's law, testing an ideal polariser, and derivation of Brewster's law | Block 1, Unit 5 | 10 | Shown above |
| 9 | Birefringence in calcite, construction and working of a Nicol prism | Block 1, Unit 5 | 10 | In full file |
| 10 | Superposition of two waves and resultant intensity, maxima and minima | Block 2, Unit 6 | 5 | In full file |
| 11 | Young's double-slit experiment and fringe width | Block 2, Unit 6 | 5 | Shown above |
| 12 | Fresnel's biprism and Lloyd's mirror, with the differences between them | Block 2, Unit 6 | 5 | In full file |
| 13 | Thin film interference and wedge-shaped film fringe conditions | Block 2, Unit 7 | 5 | In full file |
| 14 | Newton's rings and the square root relation for dark ring radii | Block 2, Unit 7 | 5 | Shown above |
| 15 | Michelson interferometer, wavelength measurement and doublet separation | Block 2, Unit 8 | 10 | In full file |
What the BPHCT-137 File Covers and What It Does Not
This file covers Blocks 1 and 2 of BPHCT-137 in depth and does not cover Blocks 3 and 4. We would rather say that on the product page than let you discover it after buying.
Blocks 1 and 2 run from Unit 1 to Unit 8 and hold waves, acoustics, electromagnetic waves, polarisation and the whole of interference. In the four sessions we analysed, these units supplied a little over half of the 50 marks on offer, which makes them the right place to concentrate first.
Blocks 3 and 4, Units 9 to 14, cover Fresnel and Fraunhofer diffraction, zone plates, diffraction gratings, the physics of lasers, holography and fibre optics. Those topics are not solved in this file. Prepare them from your Block 3 and Block 4 books, or message us and we will tell you when the diffraction and lasers companion file is ready.
Read practically, that means this file secures the Blocks 1 and 2 portion of your paper and leaves you a defined, named list of what still needs work. A guess paper that quietly implies full coverage is more dangerous than one that draws the line clearly.
How We Built the BPHCT-137 Guess Paper from Past Papers
Question selection came from reading four BPHCT-137 Term-End papers, June 2023, December 2024, June 2025 and December 2025, and recording which topic every single part tested. The shortlist follows the counts, not our instincts.
The method was mechanical on purpose. Each paper was split into its individual parts, since Question 1 alone asks you to answer any five parts of two marks and Questions 2 to 5 each offer two parts of five marks. Every part was then tagged to one of the fourteen units. The result is the grid published further down, unedited.
Two signals drove the shortlist. Repetition came first: a topic set in three or four of the four sessions is close to certain to return in some form. Absence came second: a core topic that has gone two sessions without appearing is overdue, and those rows are marked as gaps in the grid rather than dismissed as low value.
Answers were then written against the IGNOU Self Learning Material rather than a standard optics textbook. In this course that choice is not cosmetic. The book's symbol conventions, its ordering of the Brewster derivation and its treatment of the Newton's rings geometry all differ slightly from common reference texts, and the evaluator marks against the book.
Every derivation was then checked twice, once for the physics and once for whether a student could reproduce the chain of steps alone at a desk. That second check is why answers here are longer than a bare model solution would be.
BPHCT-137 Topic Frequency Analysis, June 2023 to December 2025
Six topics appeared in three or four of the last four BPHCT-137 papers, and Newton's rings and the Michelson wavelength measurement appeared in all four. The grid below is our working sheet, published whole so you can check it against your own copies of the papers.
Priority here is derived strictly from the counts. HIGH means the topic appeared in three or four sessions. MEDIUM means two. LOW means one. GAP means it did not appear in any of the four, which marks it as overdue rather than unimportant.
| Topic | Unit | Jun 2023 | Dec 2024 | Jun 2025 | Dec 2025 | Count | Priority |
|---|---|---|---|---|---|---|---|
| Wave motion, energy and power transported | 1 | Yes | No | No | No | 1 | LOW |
| Wave groups and group velocity | 1 | No | No | No | No | 0 | GAP |
| Sound waves and the one-dimensional wave equation | 1 | No | No | No | Yes | 1 | LOW |
| Standing waves on a string, harmonics | 2 | No | Yes | Yes | Yes | 3 | HIGH |
| Superposition of waves, resultant intensity | 2 | No | Yes | Yes | No | 2 | MEDIUM |
| Beats | 2 | Yes | No | No | No | 1 | LOW |
| Speed of sound, Newton's formula and Laplace's correction | 3 | Yes | No | Yes | Yes | 3 | HIGH |
| Intensity of sound and decibel level | 3 | No | No | Yes | No | 1 | LOW |
| Acoustics of buildings and reverberation | 3 | Yes | No | No | Yes | 2 | MEDIUM |
| Doppler effect for sound | 3 | No | No | Yes | No | 1 | LOW |
| Maxwell's equations and the EM wave equation | 4 | Yes | Yes | No | No | 2 | MEDIUM |
| Transverse nature of electromagnetic waves | 4 | Yes | Yes | No | No | 2 | MEDIUM |
| Huygens principle and properties of wavefronts | 4 | Yes | Yes | No | Yes | 3 | HIGH |
| Polarisation of light and its simple states | 5 | Yes | No | No | No | 1 | LOW |
| Malus's law | 5 | No | No | No | Yes | 1 | LOW |
| Brewster's law and polarisation by reflection | 5 | Yes | No | No | No | 1 | LOW |
| Double refraction and birefringence | 5 | Yes | Yes | Yes | No | 3 | HIGH |
| Nicol prism and the calcite crystal | 5 | No | Yes | Yes | No | 2 | MEDIUM |
| Wave plates, circular and elliptical polarisers | 5 | No | No | No | No | 0 | GAP |
| Young's double-slit experiment and fringe width | 6 | Yes | No | Yes | No | 2 | MEDIUM |
| Displacement of fringes by a thin sheet | 6 | Yes | No | No | No | 1 | LOW |
| Fresnel's biprism and Lloyd's mirror | 6 | Yes | No | No | Yes | 2 | MEDIUM |
| Interference in thin films and Stokes' treatment | 7 | No | No | No | No | 0 | GAP |
| Wedge-shaped film fringes | 7 | No | No | No | Yes | 1 | LOW |
| Newton's rings | 7 | Yes | Yes | Yes | Yes | 4 | HIGH |
| Michelson interferometer, working and fringes | 8 | No | Yes | Yes | No | 2 | MEDIUM |
| Michelson, wavelength and doublet separation | 8 | Yes | Yes | Yes | Yes | 4 | HIGH |
The three GAP rows are the interesting ones. Wave plates, group velocity and Stokes' treatment of thin films drew a blank across all four sessions, which usually means a return is due rather than that the topic has been retired. That is exactly why Question 13 on thin films sits in this file despite a low raw count.
BPHCT-137 Exam Pattern and Marks Distribution
BPHCT-137 is a two-hour paper for 50 marks made up of five questions of 10 marks each, all compulsory, with internal choice offered inside every question. There is no section to skip, which changes how you should revise.
| Question | Usual structure | Marks | Suggested time |
|---|---|---|---|
| Question 1 | Answer any five parts of 2 marks, spread across all four blocks | 10 | 20 minutes |
| Questions 2 to 5 | Answer any two parts of 5 marks each, occasionally a single 10-mark part | 10 each, 40 total | 22 minutes each |
| Checking | Verify units, symbols and boxed final results | Protects easily lost marks | 10 minutes |
Because every question is compulsory, a student who prepares only two blocks can still be asked something from all four. The internal choice softens this, but only within a question, so breadth matters more here than in papers where whole questions can be skipped.
Four habits carry weight with the examiner. Open with the definition or statement in the book's own wording within the first two lines. Put every formula on its own line and say what each symbol means. Draw the labelled line diagram whenever the question mentions one, since the Michelson interferometer, Nicol prism, biprism and Newton's rings figures each carry marks on their own. Close with a two-line conclusion.
Calculators are permitted and symbols carry their usual meanings. No word limit is printed on these papers, so the sensible target is around 150 words for a 5-mark part and around 250 words for a 10-mark question, which is what the answers in this file are written to.
BPHCL-138 Practical File and How It Relates to BPHCT-137
The practical component of Waves and Optics is a separate course code, BPHCL-138 Waves and Optics: Laboratory, and it is examined separately from the BPHCT-137 theory paper. Registering for the theory course does not by itself cover the laboratory requirement.
BPHCL-138 is a Discipline Specific Core laboratory course under the same Physics stream of BSCG, published as a single 108-page laboratory manual on eGyanKosh. Its experiments sit alongside the theory you are revising here, so the optics bench work reinforces the interference and polarisation units directly.
To be accurate rather than approximate: this guess paper is a theory file and does not contain the BPHCL-138 practical record. We prepare practical files for BPHCL-138 separately, written experiment by experiment with aim, apparatus, theory, observation table format, calculation and result. Message us on WhatsApp with BPHCL-138 in the message if you need the practical file rather than the theory guess paper.
One point of sequencing that trips people up: attendance at the laboratory counselling sessions and submission of the assignment are both conditions for appearing in the term-end practical examination, so do not leave BPHCL-138 to the same fortnight as your theory revision.
Get the Complete BPHCT 137 Solved Guess Paper on WhatsApp
Message 9899436384 on WhatsApp with the course code BPHCT-137 and the complete 19-page solved PDF is sent to you directly. All 15 questions, every derivation, the Michelson line diagram, the block mapping and the frequency grid are included, targeted at the June 2026 and December 2026 sessions.
Mention your session, June 2026 or December 2026, and whether you are registered under BSCG or the FYUP BSCM structure. Say so as well if you also need the BPHCL-138 practical file or the diffraction and lasers companion, and we will tell you what is ready.
BPHCT-137 Waves and Optics: Frequently Asked Questions
What is included in the BPHCT 137 Solved Guess Paper for 2026?
The BPHCT-137 file is a 19-page PDF holding 15 questions with complete worked solutions from Blocks 1 and 2 of Waves and Optics. It carries a block and unit tag on every question, the sessions in which each topic last appeared, the Michelson interferometer line diagram, marks-based word targets, a topic frequency grid and a list of low-yield topics you can safely skip.
Which sessions is the BPHCT-137 guess paper prepared for?
The BPHCT-137 guess paper targets the June 2026 and December 2026 Term-End Examinations. Question selection rests on four papers: June 2023, December 2024, June 2025 and December 2025. IGNOU holds Term-End Examinations in June and December only, so one file prepared on this cycle stays valid for both 2026 attempts rather than needing a separate version.
Does the BPHCT-137 guess paper cover diffraction, lasers and optical fibre?
No, and we say so plainly. This BPHCT-137 file covers Blocks 1 and 2, meaning Units 1 to 8. Blocks 3 and 4, which hold Fresnel and Fraunhofer diffraction, zone plates, gratings, laser physics, holography and fibre optics, are not solved here. Prepare those from your Block 3 and Block 4 books, or ask us about the companion file.
What is the exam pattern for BPHCT-137 Waves and Optics?
BPHCT-137 is a two-hour paper carrying 50 marks. There are five questions of 10 marks each and all five are compulsory, though internal choice is offered inside every question. Question 1 usually asks for any five parts of 2 marks, and Questions 2 to 5 normally offer two parts of 5 marks. Calculators are permitted.
How many blocks and units does BPHCT-137 Waves and Optics have?
BPHCT-137 has four blocks holding fourteen units, numbered continuously from 1 to 14. Block 1 is Waves, An Introduction, with five units. Block 2 is Interference, with three. Block 3 is Diffraction and Block 4 is Lasers and Optical Fibre, each with three units. Volume 1 holds Blocks 1 and 2, Volume 2 holds Blocks 3 and 4.
Is BPHCL-138 the practical course for BPHCT-137?
Yes. BPHCL-138 Waves and Optics: Laboratory is the paired practical course for BPHCT-137, and it is examined under its own course code, separately from the theory paper. Laboratory counselling attendance and assignment submission are both required before you can sit the term-end practical examination, so plan that work well ahead of your theory revision rather than alongside it.
Does the BPHCT-137 guess paper guarantee the same questions in the exam?
No guess paper can promise that, and we do not. The BPHCT-137 file names the topics with the highest probability of appearing, based on counted appearances across four past papers, plus topics that have gone missing long enough to be overdue. Numerical values and phrasing will differ in the actual paper. What carries over is the derivation method.
How do I get the full BPHCT-137 solved file after reading these samples?
Send a WhatsApp message to 9899436384 with the course code BPHCT-137 and your examination session. The complete solved PDF is shared on WhatsApp directly, so there is no account to create and no download link to wait for. If you are sitting other BSCG papers in the same session, list those course codes in the same message.