AKTU Electronic Devices · Important Questions 2026Source: ryzenstudy.com PYQs
BEC301 Electronic Devices Important Questions 2026 (AKTU)
Repeat analysis + most-asked questions, unit-wise
What we did: built from all 4 AKTU Electronic Devices papers (2021-22–2025-26): 95 questions grouped into 57 distinct questions, 23 of which were asked in more than one paper.
- of marks were repeat questions
- 51%
- of marks were repeat questions
- questions asked in 2+ papers
- 23
- questions asked in 2+ papers
- papers analysed (2021-22–2025-26)
- 4
- papers analysed (2021-22–2025-26)
- units, mapped to current syllabus
- 5
- units, mapped to current syllabus
How much of the paper repeats?
- Repeats are real: when we checked each newer BEC301 paper against the papers before it, on average 51% of its marks were questions already asked in an earlier paper.
- 2023-24 paper: 34% of marks were repeats (6 of 8 repeated questions were in our top list).
- 2025-26 paper: 69% of marks were repeats (10 of 16 repeated questions were in our top list).
- Topic weightage is a guide, not a guarantee: our Tier 1 + Tier 2 topics covered 51% of the next paper's marks — picking the same number of topics at random would have covered about 50%.
Across 10 subjects and 23 papers we tested, 43% of marks repeated earlier questions on average.
1.Unit-wise most-asked questions
Ranked by how many papers asked them, then by how recently. Click a paper to open it.
Unit 1:
17% of past marks| Question | Asked |
|---|---|
| Derive the time dependent and time independent Schrodinger wave equation. | Asked 2× |
| Define effective mass of an electron. | Asked 2× |
| State the de Broglie principle of duality. | Asked 2× |
| Differentiate between direct and indirect band gap semiconductors. Also discuss the variation of energy band with alloy composition | Asked 2× |
Unit 2:
23% of past marks| Question | Asked |
|---|---|
| Calculate the Fermi level position in Si containing 10^17 As atoms/cm3 at 300 K, assuming 50% of the impurities are ionized at this temperature. Also calculate the equilibrium electron and hole concentrations and draw the resulting band diagram. | Asked 3× |
| Using the concept of drift and diffusion of carriers, derive Einstein's relation. | Asked 3× |
| Differentiate between drift current and diffusion current in a semiconductor. | Asked 3× |
| Using the concept of drift and diffusion of carriers, derive the continuity equation. | Asked 3× |
Unit 3:
29% of past marks| Question | Asked |
|---|---|
| Light Emitting Diode (LED) | Asked 3× |
| How a PN junction diode is working? Draw and explain V-I characteristics of PN diode with neat diagrams | Asked 3× |
| Write the difference between Avalanche and Zener breakdown. | Asked 3× |
| Derive the expression of depletion width in a p-n junction. | Asked 2× |
Unit 4:
15% of past marks| Question | Asked |
|---|---|
| Draw and illustrate the Eb ers-Moll model of BJT. | Asked 4× |
| Draw and explain the input and output I-V characteristics of a BJT in Common Emitter configuration. | Asked 3× |
| A transistor has an α of 0.98. Determine the value of β. | Asked 2× |
| Determine the Q-point values of IC and VCE for the circuit in the figure. Assume VCE = 8 V, RB = 360 kOhm and RC = 2 kOhm. Also construct the dc load line and plot the Q-point (see original paper for the figure). 7 marks2025-26 Q6(a) | Asked 1× |
Unit 5:
16% of past marks| Question | Asked |
|---|---|
| Explain the construction, working and characteristics of n-channel Enhancement Type MOSFET. | Asked 4× |
| Define MOS capacitor and explain its basic structure. | Asked 2× |
| Draw the small signal model of NMOS transistor. | Asked 2× |
| Explain the construction and principle of operation of N-channel JFET. Draw its drain and transfer characteristics. 7 marks2025-26 Q2(e) | Asked 1× |
2.Topic weightage: which topics carry the marks
Blue = Tier 1 + Tier 2 (topics that carried ~80% of past marks). Grey = the rest. It shows where marks have gone, not a promise of what comes next.
LED, photodiode, solar cell · U3
9.6% (cum 10%)
Quantum mechanics review · U1
7.6% (cum 17%)
MOSFET operation and models · U5
7.5% (cum 25%)
Fermi level and carrier concentration · U2
7.2% (cum 32%)
PN diode I-V characteristics · U3
6% (cum 38%)
PN junction basics · U3
5.6% (cum 44%)
Ebers-Moll model · U4
5.2% (cum 49%)
E-k diagrams and band gap · U1
4.7% (cum 53%)
MOS capacitor and C-V · U5
4.7% (cum 58%)
Diffusion and Einstein relation · U2
4.5% (cum 63%)
Poisson and continuity equations · U2
4% (cum 67%)
Breakdown and Zener diode · U3
4% (cum 71%)
BJT I-V characteristics · U4
3.7% (cum 74%)
Intrinsic and extrinsic bands · U2
2.8% (cum 77%)
Effective mass · U1
2.7% (cum 80%)
Drift, mobility and resistivity · U2
2.6% (cum 82%)
Schottky diode · U3
2.5% (cum 85%)
FET DC biasing · U5
2.5% (cum 87%)
BJT DC biasing · U4
2.5% (cum 90%)
BJT configurations · U4
1.9% (cum 92%)
Electrons in periodic lattices · U1
1.8% (cum 94%)
Small signal and switching models · U3
1.5% (cum 95%)
Bias stability · U4
1.5% (cum 97%)
FET and JFET · U5
1.4% (cum 98%)
Generation and recombination · U2
1.2% (cum 99%)
Sheet resistance · U2
1% (cum 100%)
| Topic | Papers | Share |
|---|---|---|
| LED, photodiode, solar cell · Unit 3 · Tier 1 | 4/4 | 9.6% |
| Quantum mechanics review · Unit 1 · Tier 1 | 3/4 | 7.6% |
| MOSFET operation and models · Unit 5 · Tier 1 | 4/4 | 7.5% |
| Fermi level and carrier concentration · Unit 2 · Tier 1 | 3/4 | 7.2% |
| PN diode I-V characteristics · Unit 3 · Tier 1 | 4/4 | 6% |
| PN junction basics · Unit 3 · Tier 1 | 3/4 | 5.6% |
| Ebers-Moll model · Unit 4 · Tier 1 | 4/4 | 5.2% |
| E-k diagrams and band gap · Unit 1 · Tier 1 | 3/4 | 4.7% |
| MOS capacitor and C-V · Unit 5 · Tier 2 | 3/4 | 4.7% |
| Diffusion and Einstein relation · Unit 2 · Tier 2 | 4/4 | 4.5% |
| Poisson and continuity equations · Unit 2 · Tier 2 | 3/4 | 4% |
| Breakdown and Zener diode · Unit 3 · Tier 2 | 3/4 | 4% |
| BJT I-V characteristics · Unit 4 · Tier 2 | 3/4 | 3.7% |
| Intrinsic and extrinsic bands · Unit 2 · Tier 2 | 1/4 | 2.8% |
| Effective mass · Unit 1 · Tier 2 | 3/4 | 2.7% |
| Drift, mobility and resistivity · Unit 2 · Tier 2 | 3/4 | 2.6% |
| Schottky diode · Unit 3 · Tier 3 | 2/4 | 2.5% |
| FET DC biasing · Unit 5 · Tier 3 | 2/4 | 2.5% |
| BJT DC biasing · Unit 4 · Tier 3 | 2/4 | 2.5% |
| BJT configurations · Unit 4 · Tier 3 | 3/4 | 1.9% |
| Electrons in periodic lattices · Unit 1 · Tier 3 | 2/4 | 1.8% |
| Small signal and switching models · Unit 3 · Tier 3 | 1/4 | 1.5% |
| Bias stability · Unit 4 · Tier 3 | 1/4 | 1.5% |
| FET and JFET · Unit 5 · Tier 3 | 1/4 | 1.4% |
| Generation and recombination · Unit 2 · Tier 3 | 1/4 | 1.2% |
| Sheet resistance · Unit 2 · Tier 3 | 2/4 | 1% |
3.Paper pattern (2025-26)
| Section | Questions | Rule |
|---|---|---|
| A | 7 × 2 marks | Attempt all |
| B | 5 × 7 marks | Attempt any 3 |
| C | 11 × 7 marks | Attempt any 1 |
4.Study order
- 1LED, photodiode, solar cell (Unit 3, Tier 1)
- 2Quantum mechanics review (Unit 1, Tier 1)
- 3MOSFET operation and models (Unit 5, Tier 1)
- 4Fermi level and carrier concentration (Unit 2, Tier 1)
- 5PN diode I-V characteristics (Unit 3, Tier 1)
- 6PN junction basics (Unit 3, Tier 1)
- 7Ebers-Moll model (Unit 4, Tier 1)
- 8E-k diagrams and band gap (Unit 1, Tier 1)
- 9MOS capacitor and C-V (Unit 5, Tier 2)
- 10Diffusion and Einstein relation (Unit 2, Tier 2)
- 11Poisson and continuity equations (Unit 2, Tier 2)
- 12Breakdown and Zener diode (Unit 3, Tier 2)
- 13BJT I-V characteristics (Unit 4, Tier 2)
- 14Intrinsic and extrinsic bands (Unit 2, Tier 2)
- 15Effective mass (Unit 1, Tier 2)
- 16Drift, mobility and resistivity (Unit 2, Tier 2)
FAQ
Which units of BEC301 carry the most marks?
Unit 3 (, 29% of past marks) and Unit 2 (, 23% of past marks).
Do AKTU Electronic Devices questions repeat?
Yes. On average 51% of the marks in each newer BEC301 paper came from questions already asked in an earlier paper, and 23 questions have appeared in more than one paper.
How is this list made?
Every question from the 4 papers (2021-22–2025-26) was mapped to the current AKTU syllabus and grouped with the same question from other years. Questions are ranked by how many papers they appeared in, then by how recently.
Study this subject
Note: this is based on past AKTU papers, not a guarantee. Questions are mapped to the current syllabus; topics that are no longer in the syllabus are left out.