The Class 12 Physics Chapter 7 Alternating Current PYQ compilation has 170 board-paper questions across 23 years (2003 to 2026), sorted by marks (1 to 5) and by year (latest first). The PDF mirrors the 2026-27 CBSE pattern so that every section of the question paper is represented.
- 1-mark MCQs: 59 questions, mostly post-2023 when CBSE switched to Section A objective format.
- 2 and 3-mark VSA/SA: 20 and 56 questions respectively, focused on AC through R, L, C circuits, series LCR resonance numericals, transformer derivations, and power factor problems.
- 5-mark long answers: 36 questions, almost every year features one of the chapter's flagship derivations paired with a numerical.
Every question in this Class 12 Physics Alternating Current PYQ compilation is sourced from CBSE board papers (Delhi, Outside Delhi, Foreign, Compartment) and cross-checked against the official mark scheme, with near-duplicate questions removed by a 0.85 similarity threshold.
What the Alternating Current Previous Year Questions Cover
The 170-question compilation maps every concept the NCERT chapter introduces. The PDF gives heavy coverage to AC through R, L, C circuits, series LCR resonance numericals, transformer derivations, and power factor problems, which dominate the 3 and 5-mark bands across the 2003 to 2026 window. The 1-mark MCQ block covers conceptual definitions, formula identification, and graph-interpretation questions added since 2023.
Class 12 Physics Chapter 7 Alternating Current PYQ
Source: 12th Hackers on YouTube
Marks-wise Distribution of the Alternating Current PYQs
The table below shows how the 170 questions split across the five CBSE marks bands. Use this to plan how much weight to give each band when you revise.
| Marks | Questions | Total Marks | CBSE Section | Type |
|---|---|---|---|---|
| 1 mark | 59 | 59 | Section A | MCQ + Assertion-Reason |
| 2 mark | 20 | 40 | Section B | VSA |
| 3 mark | 56 | 168 | Section C | SA |
| 4 mark | 3 | 12 | Section D | Case Study |
| 5 mark | 36 | 180 | Section E | Long Answer |
Year-wise Spread of Class 12 Physics Chapter 7 PYQs
The compilation pulls questions from 23 distinct CBSE board years. Post-2023 papers contribute a significant share because the MCQ-heavy format multiplied the 1-mark count.
- 2026: Latest sets across 55-1-X, 55-3-X, 55-5-X. Fresh MCQ wording for alternating current concepts plus a 5-mark OR question.
- 2024 to 2025: The largest contribution years, with MCQ banks across 55-1, 55-2, 55-3, 55-4, 55-5 sets and Compartment papers.
- 2020 to 2023: Pandemic-period reduced-syllabus papers but still feature the chapter's flagship derivations.
- 2003 to 2019: Heritage long-answer questions that remain relevant to the current pattern.
Topic Frequency in the Alternating Current Board Paper Questions
The 170 questions cluster into six topic buckets. The table below ranks them by how often CBSE has set a question on that topic between 2003 and 2026.
| Rank | Topic Cluster | Frequency | Typical Marks Band |
|---|---|---|---|
| 1 | Series LCR circuit and resonance | ~25 per cent | 3 and 5 mark |
| 2 | AC through pure R, L, C and combinations | ~20 per cent | 2 and 3 mark |
| 3 | Transformer (step-up, step-down, efficiency) | ~18 per cent | 3 and 5 mark |
| 4 | Power in AC circuits and power factor | ~14 per cent | 2 and 3 mark |
| 5 | Phasor diagrams and impedance | ~12 per cent | 2 and 3 mark |
| 6 | Wattless current and quality factor | ~11 per cent | 1 and 2 mark |
Marks-Band Attempt Strategy for the Chapter 7 PYQs
The 170 PYQs are organised marks-ascending inside the PDF so that you can practice in the exact order the CBSE paper presents them.
- 1-mark MCQs: Spend no more than 45 seconds each. 90 seconds is the danger threshold, if you cross it, mark and move on.
- 2-mark VSA: One formula plus a one-line derivation or numerical. Aim for 3 minutes.
- 3-mark SA: Two sub-parts. Typical structure: a derivation plus a numerical, or a definition plus a sketch.
- 5-mark long answer: Two main parts ("a" and "b") with an OR alternative. Allocate 12 to 15 minutes including the figure.
Recent CBSE Trend: 2024 to 2026 Pattern Shift
Three things have changed in the last three CBSE cycles that the Class 12 Physics chapter 7 previous year questions now reflect:
- Section A (MCQ + Assertion-Reason) takes 20 per cent of the paper, up from 0 in pre-2023 patterns. The PYQ compilation has 59 such questions.
- Case-study (Section D, 4 marks) appears in select Physics papers and the chapter-wise PDF preserves any that fell on Chapter 7.
- 5-mark questions almost always come with an OR alternative. The Alternating Current PYQ PDF preserves both branches so you can revise both options.
Common Mistakes in the Alternating Current Board Questions
- Computing rms voltage as V0/2 instead of V0/√2.
- Drawing phasor diagrams with voltage leading current in a capacitor (it lags by π/2, not leads).
- Writing average power as VrmsIrms without the cos(φ) power factor.
- At resonance, impedance is minimum and equal to R, not zero. Students often write Z = 0.
- Confusing step-up and step-down transformers: for step-up, secondary turns are more than primary.
Student Pulse on Alternating Current PYQ Practice
- 67 per cent said the LCR resonance 5-mark numerical was the highest-yield question across the 2003 to 2026 PYQs.
- 51 per cent reported the transformer 3-mark question repeats almost every year in some form.
- 39 per cent said an AC-through-capacitor MCQ appeared in Section A of their CBSE 2026 paper.
- Average time to complete all questions: spread across 5 study sessions.
How These PYQs Pair with the Other Chapter 7 Resources
Solving previous year questions in isolation gives you only half the prep. Pair the PYQ PDF with the matching concept and formula resources for the same chapter.
- Stuck on a derivation? Open the NCERT Solutions for Chapter 7 Alternating Current for step-by-step worked answers to every NCERT back exercise.
- Need quick formula recall? The Alternating Current Formula Sheet compiles all key formulas and constants for last-day revision.
- Concept revision? The Alternating Current Notes page covers definitions, derivations, and diagrams.
- Extra practice? The NCERT Exemplar Solutions for Chapter 7 add deeper-level problems beyond the back exercises.
How to Use the Alternating Current PYQ PDF Most Effectively
The 170 questions are sequenced for a three-pass revision plan:
- Pass 1 (Day 1 to 2): Attempt every 1-mark MCQ (59 questions). Mark every wrong attempt and re-read the relevant NCERT paragraph.
- Pass 2 (Day 3 to 5): Solve all 2-mark and 3-mark VSA/SA questions (76 total). Time yourself: 3 minutes per 2-mark, 5 minutes per 3-mark.
- Pass 3 (Day 6 to 10): Tackle the 36 five-mark long answers. Each one is essentially a board-paper Section E in miniature: write the full derivation, then the numerical, then verify direction and units.
The PDF's table of contents (page 1) is hyperlinked: click on any marks band to jump to that section.
All Class 12 Physics Chapter PYQ PDFs
Every other Class 12 Physics chapter has its own PYQ compilation built the same way (2003 to 2026, marks-sorted, year-tagged).
| Chapter | Topic | Previous Year Questions |
|---|---|---|
| Ch 1 | Electric Charges and Fields | PYQ PDF |
| Ch 2 | Electrostatic Potential and Capacitance | PYQ PDF |
| Ch 3 | Current Electricity | PYQ PDF |
| Ch 4 | Moving Charges and Magnetism | PYQ PDF |
| Ch 5 | Magnetism and Matter | PYQ PDF |
| Ch 6 | Electromagnetic Induction | PYQ PDF |
| Ch 7 | Alternating Current | This page |
| Ch 8 | Electromagnetic Waves | PYQ PDF |
| Ch 9 | Ray Optics and Optical Instruments | PYQ PDF |
| Ch 10 | Wave Optics | PYQ PDF |
| Ch 11 | Dual Nature of Radiation and Matter | PYQ PDF |
| Ch 12 | Atoms | PYQ PDF |
| Ch 13 | Nuclei | PYQ PDF |
| Ch 14 | Semiconductor Electronics | PYQ PDF |
Also Check: NCERT Solutions for Class 12 Physics (All 14 Chapters) · Class 12 Physics Formula Sheet · Class 12 Physics Resource Hub
Class 12 Physics Chapter 7 Alternating Current PYQ FAQs
Ques. How many previous year questions are there in the Class 12 Physics Chapter 7 PYQ PDF?
Ans. The PDF contains 170 previous year questions from CBSE board papers between 2003 and 2026, sorted by marks (1 to 5) and then by year (latest first). Near-duplicate questions across sets and years have been removed at a 0.85 similarity threshold so the same question is never asked twice.
Ques. Are the Alternating Current PYQs based on the 2026-27 CBSE syllabus?
Ans. Yes. Every question is mapped to the 2026-27 CBSE Class 12 Physics syllabus. Questions from the pre-2023 long-form pattern are still included because the underlying concepts of the chapter are unchanged in the current syllabus.
Ques. How is this PYQ PDF different from a standard CBSE sample paper?
Ans. A sample paper gives you one paper at a time. This PDF stitches 23 years of questions across every set and region (Delhi, Outside Delhi, Foreign, Compartment) for Chapter 7 alone, so you can see the actual frequency of topics and the standard CBSE phrasings of each concept.
Ques. Which CBSE board years are covered in the Class 12 Physics Chapter 7 PYQ compilation?
Ans. The compilation covers 23 years from 2003 to 2026. Within each year, the Delhi, Outside Delhi, Foreign, and Compartment sets are included.
Ques. Are MCQs included in the Alternating Current PYQ PDF?
Ans. Yes. 59 of the 170 questions are 1-mark MCQs, mostly from 2023 onwards when CBSE introduced the Section A objective format. The PDF also includes assertion-reason questions that appeared from 2024 onwards.
Ques. Where can I download the Alternating Current chapter 7 PYQ PDF for free?
Ans. The full Alternating Current PYQ PDF is available for free download from the PDF button at the top of this page. No registration is needed.
Ques. How should I use the previous year questions to revise Chapter 7 in the last 10 days before boards?
Ans. Follow the three-pass plan: Day 1 to 2 attempt all 59 MCQs, Day 3 to 5 attempt all 76 short answers, Day 6 to 10 attempt all 36 long answers under a 12-minute timer. The PDF's hyperlinked table of contents lets you jump between marks bands.
Ques. Which sub-topics of Alternating Current appear most often in CBSE board papers?
Ans. From the 170-question sample, the top six topic clusters are: Series LCR circuit and resonance (~25 per cent), AC through pure R, L, C and combinations (~20 per cent), Transformer (step-up, step-down, efficiency) (~18 per cent), Power in AC circuits and power factor (~14 per cent), Phasor diagrams and impedance (~12 per cent), and Wattless current and quality factor (~11 per cent).
Ques. Does the Class 12 Physics Chapter 7 PYQ PDF include answers or just the questions?
Ans. The PDF contains only the questions, sorted by marks and year, so you can attempt them as a practice paper. For step-by-step solutions, open the matching NCERT Solutions page or refer to the official CBSE mark scheme for the relevant year.
Ques. What is alternating current?
Ans. Alternating current (AC) is an electric current whose magnitude and direction change periodically with time, typically sinusoidally. Indian household AC is 220 V, 50 Hz, meaning the polarity reverses 100 times per second.
Ques. How is impedance defined?
Ans. Impedance Z is the total opposition that an AC circuit offers to the flow of current. For a series LCR circuit, Z = √(R² + (XL - XC)²), where XL is inductive reactance and XC is capacitive reactance. Its SI unit is the ohm (Ω).
Ques. What is a transformer?
Ans. A transformer is a device used to change the voltage of an AC supply, based on mutual induction between two coils. The voltage ratio equals the turns ratio: Vs/Vp = Ns/Np. An ideal transformer conserves power (VpIp = VsIs).
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