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Sunday, 25 October

JEE Main · Physics · Class 12

Communication Systems: JEE Main previous year questions

This chapter is not in NTA's JEE Main 2026 syllabus. It had 56 questions in the shifts Lumi analysed; they are kept here for reference.

Questions
56
in 56 of 108 shifts · 5 of 8 years
Average a shift
0.4
of 25 Physics · 0.0 since 2024 -0.6
Typical range
0.0–0.8
questions a shift; fewest 0.0, most 0.8
Syllabus
Dropped
NTA JEE Main 2026 syllabus
  • Typical range (fact)
  • Average a shift (fact)
  • Weighted estimate (model)

Questions are counted per shift, out of the 25 each subject has, in the shifts Lumi analysed; papers that offered 30 a subject (2017, 2021–2024) are scaled to 25. Typical range: the middle six of the eight years (2017, 2020–2026), leaving out the single highest and lowest year. The average and the range are historical fact. The weighted estimate is a model: each year's share, with recent years counting more (half-life three years), and chapters NTA dropped from the syllabus set near zero. It is a guide to effort, not a forecast of the paper.

Key findings

Communication Systems at a glance

  1. 01

    25%

    of its questions asked for a numerical answer, 0.8 times the Physics average.

  2. 02

    0%

    of its questions were rated hard, against 5% across all Physics questions in the same shifts.

Questions a shift, year by year

Out of the 25 Physics questions in a shift. Years differ in how many shifts Lumi analysed, so each year is scaled to one shift.

0240.8’170.1’200.7’210.8’220.8’230’240’250’26

Raw count: 2017: 1 in 1 shift · 2020: 1 in 12 shifts · 2021: 21 in 24 shifts · 2022: 22 in 24 shifts · 2023: 11 in 12 shifts · 2024: 0 in 18 shifts · 2025: 0 in 8 shifts · 2026: 0 in 9 shifts.

Kind of question

SHARE OF QUESTIONS
  • Calculation38%
  • Numerical answer25%
  • Recall, single correct13%
  • Application9%
  • Match the list7%
  • Conceptual4%
  • Multi-step2%
  • Two statements2%
  • Diagram based2%

Most common asks: antenna height from line-of-sight range (2); amplitudes of amplitude modulated wave (2); line of sight range from antenna heights (2).

Profile

This chapter in numbers

Where it ranks, how steady it is, and what it costs to study.

Syllabus
Dropped
NTA JEE Main 2026
Last asked
2023
Share of Physics
1.6%
of its questions, all shifts analysed
Busiest year
2017
0.8 questions a shift
Year to year
Swings a lot
varies by about 0.4 questions a shift
Long-run direction
-0.09
questions a shift, per year
Easy questions
66%
0% rated hard
Numerical answer
25%
0.8× the Physics rate
With a figure
2%
graph, diagram or structure
Foundation for others
50%
of its ideas are used in other chapters

Difficulty, year by year

Each question rated easy, medium or hard. Each bar is that year’s split, so years compare directly; the number is the questions in that year’s analysed shifts (1 to 24 shifts a year).

  • 20171
  • 20201
  • 202121
  • 202222
  • 202311
  • 2024
  • 2025
  • 2026
  • Easy
  • Medium
  • Hard

What it asks you to do

SHARE OF QUESTIONS
  • Calculation63%
  • Recall20%
  • Application11%
  • Conceptual4%
  • Data or graph2%
  • Multi-step2%

Every question

All 56 Communication Systems questions

Newest first, shift by shift. The newest 40 show their opening words; older ones name the idea they tested. Each opens with its options and the official answer.

JEE Main 202311 questions

  1. 6 Apr 2023, Shift 1 · Q31By what percentage will the transmission range of a TV tower be affected when the height of the tower is increased by 21% ?EasySingle correct
  2. 6 Apr 2023, Shift 2 · Q41For an amplitude modulated wave the minimum amplitude is 3 V, while the modulation index is 60%. The maximum amplitude of the modulated…EasySingle correct
  3. 8 Apr 2023, Shift 1 · Q41A TV transmitting antenna is 98 m98\ \mathrm{m} high and the receiving antenna is at the ground level. If the radius of the earth is…MediumSingle correct
  4. 10 Apr 2023, Shift 1 · Q42A carrier wave of amplitude 15 V is modulated by a sinusoidal base band signal of amplitude 3 V. The ratio of maximum amplitude to minimum…EasySingle correct
  5. 10 Apr 2023, Shift 2 · Q42A message signal of frequency 3kHz is used to modulate a carrier signal of frequency 1.5 MHz. The bandwidth of the amplitude modulated…EasySingle correct
  6. 11 Apr 2023, Shift 1 · Q31A transmitting antenna is kept on the surface of the earth. The minimum height of receiving antenna required to receive the signal in line…EasySingle correct
  7. 11 Apr 2023, Shift 2 · Q41In satellite communication, the uplink frequency band used is :EasySingle correct
  8. 12 Apr 2023, Shift 1 · Q34The amplitude of 15 sin (1000 π\pit) is modulated by 10 sin (4 π\pit) signal. The amplitude modulated signal contains frequencies of A.…MediumOther
  9. 13 Apr 2023, Shift 1 · Q48Match List - I with List - II List - I (Layer of atmosphere) | List - II (Approximate height over earth's surface) (A) F1F_1 - Layer | (I)…EasyMatch the list
  10. 13 Apr 2023, Shift 2 · Q50To radiate EM signal of wavelength λ\lambda with high efficiency, the antennas should have a minimum size equal to :EasySingle correct
  11. 15 Apr 2023, Shift 1 · Q42The height of transmitting antenna is 180 m and the height of the receiving antenna is 245 m. The maximum distance between them for…EasySingle correct

JEE Main 202222 questions

  1. 25 Jul 2022, Shift 1 · Q60The required height of a TV tower which can cover the population of 6.036.03 lakh is hh. If the average population density is 100100 per…MediumNumerical value
  2. 25 Jul 2022, Shift 2 · Q31In AM modulation, a signal is modulated on a carrier wave such that maximum and minimum amplitudes are found to be 6 V and 2 V…EasySingle correct
  3. 26 Jul 2022, Shift 2 · Q39The maximum and minimum voltage of an amplitude modulated signal are 60 V and 20 V respectively. The percentage modulation index will be :EasySingle correct
  4. 27 Jul 2022, Shift 1 · Q50At a particular station, the TV transmission tower has a height of 100 m. To triple its coverage range, height of the tower should be…EasySingle correct
  5. 27 Jul 2022, Shift 2 · Q50A square wave of the modulating signal is shown in the figure. The carrier wave is given by C(t)=5sin⁡(8 πt)C(t)=5\sin(8\,\pi t) Volt. The modulation…MediumDiagram basedHas a figure
  6. 28 Jul 2022, Shift 1 · Q50In the case of amplitude modulation to avoid distortion the modulation index (μ\mu) should be :EasySingle correct
  7. 28 Jul 2022, Shift 2 · Q20A FM Broad cast transmitter, using modulating signal of frequency 20 kHz has a deviation ratio of 10. The Bandwidth required for…EasySingle correct
  8. 29 Jul 2022, Shift 1 · Q48Find the modulation index of an AM wave having 8 V variation where maximum amplitude of the AM wave is 9 V.EasySingle correct
  9. 29 Jul 2022, Shift 2 · Q55A modulating signal 2sin⁡(6.28×106)t2\sin(6.28\times10^{6})t is added to the carrier signal 4sin⁡(12.56×109)t4\sin(12.56\times10^{9})t for amplitude modulation. The…MediumNumerical value
  10. 30 Jul 2022, Shift 2 · Q20An amplitude modulate wave consists of following components : Carrier component = 5 V peak value Lower side band component = 2.5 V peak…EasySingle correct
  11. 24 Jun 2022, Shift 1 · Q46A baseband signal of 3.5 MHz frequency is modulated with a carrier signal of 3.5 GHz frequency using amplitude modulation method. What…MediumSingle correct
  12. 25 Jun 2022, Shift 1 · Q48A signal of 100 THz frequency can be transmitted with maximum efficiency by :EasySingle correct
  13. 25 Jun 2022, Shift 2 · Q49Match List I with List II List I | List II A. Facsimile | I. Static Document Image B. Guided media Channel | II. Local Broadcast Radio C.…EasyMatch the list
  14. 26 Jun 2022, Shift 1 · Q50Choose the correct statement for amplitude modulation :EasySingle correct
  15. 26 Jun 2022, Shift 2 · Q50A sinusoidal wave y(t)=40sin⁡(10×106 πt)y(t) = 40\sin(10 \times 10^{6}\ \pi t) is amplitude modulated by another sinusoidal wave x(t)=20sin⁡(1000πt)x(t) = 20\sin(1000\pi t).…MediumSingle correct
  16. 27 Jun 2022, Shift 1 · Q58The height of a transmitting antenna at the top of a tower is 25 m and that of receiving antenna is, 49 m. The maximum distance between…MediumNumerical value
  17. 27 Jun 2022, Shift 2 · Q50We do not transmit low frequency signal to long distances because- (a) The size of the antenna should be comparable to signal wavelength…MediumOther
  18. 28 Jun 2022, Shift 1 · Q49Match List-I with List-II List - I | List - II A. Television signal | I. 03 KHz B. Radio signal | II. 20 KHz C. High Quality Music | III.…EasyMatch the list
  19. 28 Jun 2022, Shift 2 · Q50Amplitude modulated wave is represented by VAM=10[1+0.4cos⁡(2π×104t)]cos⁡(2π×107t)V_{AM}=10\left[1+0.4\cos(2\pi\times10^{4}t)\right]\cos(2\pi\times10^{7}t). The total…EasySingle correct
  20. 29 Jun 2022, Shift 1 · Q50Only 2% of the optical source frequency is the available channel bandwidth for an optical communicating system operating at 1000 nm. If an…MediumSingle correct
  21. 29 Jun 2022, Shift 2 · Q41The TV transmission tower at a particular station has a height of 125 m. For doubling the coverage of its range, the height of the tower…MediumSingle correct
  22. 30 Jun 2022, Shift 1 · Q49A speech signal given by 11 sin (2200 π\pit)V is used for amplitude modulation with a carrier signal given by 44 sin(6600 π\pit)V. The…EasySingle correct

JEE Main 202121 questions

  1. 4 Aug 2021, Shift 1 · Q8A television transmission tower has a height of 250 m. The approximate distance upto which the broadcast can be received is (Assume the…EasySingle correct
  2. 4 Aug 2021, Shift 2 · Q21An Amplitude Modulated (AM) wave is expressed as C=5(1+0.3cos⁡200πt)cos⁡(1×108 πt)C=5(1+0.3\cos200\pi t)\cos(1\times10^8\,\pi t) volts. Its percentage modulation is…EasyNumerical value
  3. 26 Aug 2021, Shift 1 · Q28An amplitude modulated wave is represented by Cm(t)=10(1+0.2cos⁡12560t)sin⁡(111×104t)C_m(t)=10(1+0.2\cos 12560t)\sin(111\times10^{4}t) volts. The modulating frequency in kHz…EasyNumerical value
  4. 26 Aug 2021, Shift 2 · Q2A transmitting antenna at top of a tower has a height of 50 m and the height of receiving antenna is 80 m. What is the range of…EasySingle correct
  5. 27 Aug 2021, Shift 1 · Q29A transmitting antenna has a height of 320 m and that of receiving antenna is 2000 m. The maximum distance between them for satisfactory…MediumNumerical value
  6. 27 Aug 2021, Shift 2 · Q20An antenna is mounted on a 400 m tall building. What will be the wavelength of signal that can be radiated effectively by the transmission…MediumSingle correct
  7. 31 Aug 2021, Shift 1 · Q30If the sum of the heights of transmitting and receiving antennas in the line of sight of communication is fixed at 160 m, then the maximum…MediumNumerical value
  8. 31 Aug 2021, Shift 2 · Q25Open the question · Easy · Numerical value
  9. 24 Feb 2021, Shift 1 · Q27Open the question · Easy · Numerical value
  10. 25 Feb 2021, Shift 1 · Q8Open the question · Medium · Two statements
  11. 25 Feb 2021, Shift 2 · Q17Open the question · Easy · Single correct
  12. 26 Feb 2021, Shift 1 · Q29Open the question · Easy · Numerical value
  13. 26 Feb 2021, Shift 2 · Q25Open the question · Easy · Numerical value
  14. 22 Jul 2021, Shift 2 · Q1Open the question · Medium · Single correct
  15. 25 Jul 2021, Shift 1 · Q4Open the question · Easy · Single correct
  16. 25 Jul 2021, Shift 2 · Q30Open the question · Easy · Numerical value
  17. 16 Mar 2021, Shift 2 · Q1Open the question · Medium · Single correct
  18. 17 Mar 2021, Shift 1 · Q21Open the question · Medium · Numerical value
  19. 17 Mar 2021, Shift 2 · Q1Open the question · Easy · Single correct
  20. 18 Mar 2021, Shift 1 · Q18Open the question · Easy · Match the list
  21. 18 Mar 2021, Shift 2 · Q29Open the question · Medium · Numerical value

JEE Main 20201 question

  1. 2 Sep 2020, Shift 1 · Q19Open the question · Easy · Single correct

JEE Main 20171 question

  1. 2 Apr 2017 (offline) · Q28Open the question · Easy · Single correct

Questions from the official JEE Main papers published by NTA. Chapter, topic and idea tags, counts and notes are Lumi’s. Pattern: Asked most years.

More Physics, Class 12

All JEE Main chaptersJEE Main Physics analysisStudy plan