JEE Main · Physics · Semiconductor Electronics: Materials, Devices and Simple Circuits

Transistors: JEE Main previous year questions

Name: Transistors: JEE Main previous year questions
Creator: Lumi

21 questions in the 108 JEE Main shifts Lumi analysed, in 5 of 8 years. Pattern: Gone quiet. 0 came in 2024–26. Here is how it is asked and which ideas come back.

Questions: 21; in 20 of 108 shifts
Years asked: 5/8; last asked 2023
Since 2024: Quiet; 0 questions in 2024–26
Weighted estimate: –; history: 0.2 a shift on average, typically 0.0–0.3

Key findings

01
Asked in 5 of 8 years with analysed shifts and in 20 of 108 shifts: 21 questions, #142 of 196 topics. The years that asked it were 1.5 apart on average. Last asked in 2023.
02
60% of its questions since 2020 tested an idea no earlier year had asked; 6 repeated an idea from the year before.
03
The most repeated idea is CE Amplifier Voltage Gain, asked 7 times in 7 shifts (2021, 2022, 2023), most often as “current gain from power gain in ce amplifier”.
04
JEE Main has asked 10 of the 54 ideas in this topic; 42 have never been asked, directly or inside another question.
05
Mostly asked as single correct (52%); 38% need a numerical answer, 67% are easy and 0% hard. It went down from 0.3 to 0.0 questions a shift since 2024.
06
The skill tested most is calculation (38%), then data or graph (24%).

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.

Raw count: 2017: 1 in 1 shift · 2020: 1 in 12 shifts · 2021: 7 in 24 shifts · 2022: 9 in 24 shifts · 2023: 3 in 12 shifts · 2024: 0 in 18 shifts · 2025: 0 in 8 shifts · 2026: 0 in 9 shifts.

Up to 2023: 0.3; a shift, of 25
Since 2024: 0.0; -0.3
Usual gap: 1.5 yrs; between years asking it
Shifts with it: 20/108; 19% of analysed shifts

How it is asked

Difficulty, format and skill

Across all 21 questions on Transistors since 2017.

Difficulty

QUESTIONS

147

Easy14 · 67%
Medium7 · 33%
Hard0 · 0%

Format

Single correct · 11 Q52%
Numerical value · 8 Q38%
Assertion–reason · 1 Q5%
Two statements · 1 Q5%

Skill tested

Calculation · 8 Q38%
Data or graph · 5 Q24%
Conceptual · 4 Q19%
Recall · 4 Q19%

Repeats

New idea, or one asked before?

Each column is a year. Blue questions tested an idea no earlier year had asked; navy ones went back to an idea from an earlier year. 2017 is the first year, so everything in it counts as new. Heights are question counts, and Lumi analysed 1 to 24 shifts a year, so compare the split inside a column rather than heights across years.

’17’20’21’22’23’24’25’26

Idea asked for the first time
Idea asked in an earlier year

Coverage of the topic

JEE Main has asked 10 of the 54 ideas in this topic. 42 have never been asked yet.

1042

Asked directly10 · 19%
Touched inside another question2 · 4%
Never asked42 · 78%

Ideas come from Lumi’s JEE syllabus map. A never-asked idea is not a safe skip: across all of JEE Main, 22% of questions since 2024 tested an idea no earlier year had asked.

Drill down

Idea, year, question

Every idea JEE Main tested in this topic, with its eight years. Open one to read the questions.

ideaAskedShareYears’17’20’21’22’23’24’25’26

OpenRepeated7 · 33%33%3/842
- 8 Apr ’23 S2 · Q43
  For a given transistor amplifier circuit in CE configuration $V_{CC} = 1$ V, $R_C = 1$ k $\Omega$ , $R_b = 100$ k $\Omega$ and $\beta = 100$ .…
  easySingle correctAsked the year before
- 13 Apr ’23 S1 · Q59
  From the given transfer characteristic of a transistor in CE configuration, the value of power gain of this configuration is $10^x$ , for…
  mediumNumerical valueAsked the year before
- 26 Jul ’22 S2 · Q56
  The typical transfer characteristics of a transistor in CE configuration is shown in figure. A load resistor of 2 $k\Omega$ is connected…
  mediumNumerical valueAsked the year before
- 28 Jul ’22 S2 · Q19
  An n.p.n transistor with current gain $\beta$ = 100 in common emitter configuration is shown in figure. The output voltage of the…
  mediumSingle correctAsked the year before
- 24 Jun ’22 S1 · Q53
  A transistor is used in common-emitter mode in an amplifier circuit. When a signal of 10 mV is added to the base-emitter voltage, the base…
  easyNumerical valueAsked the year before
- 25 Jun ’22 S2 · Q60
  In an experiment of $CE$ configuration of n-p-n transistor, the transfer characteristics are observed as given in figure. If the input…
  mediumNumerical valueAsked the year before
- 18 Mar ’21 S1 · Q21
  An npn transistor operates as a common emitter amplifier with a power gain of $10^6$ . The input circuit resistance is 100 $\Omega$ and the…
  mediumNumerical valueNew idea
OpenRepeated4 · 19%19%2/83
OpenRepeated2 · 10%10%2/8
Open2 · 10%10%1/82
Open1 · 5%5%1/8
Open1 · 5%5%1/8
Open1 · 5%5%1/8
Open1 · 5%5%1/8
Open1 · 5%5%1/8
Open1 · 5%5%1/8

Squares are the 8 years with analysed shifts, 2017 to 2026. A number is the questions that year when there is more than one; the shade is scaled to one shift, so a year with more analysed shifts (1 to 24 a year) does not look darker. Share is of the level above.

Ideas

Every idea inside this topic

10 different ideas were tested; 4 came more than once.

CE Amplifier Voltage Gain7×
current gain from power gain in ce amplifier
Numerical value · 7 shifts · 5 numerical
Current Gains Alpha and Beta4×
current gain from collector and base change
Single correct · 4 shifts
AC vs DC Current Gain2×
ac current gain from output characteristics
Numerical value · 2 shifts · 1 numerical
Transistor Biasing and Structure2×
operating region of transistor amplifier
Single correct · 2 shifts
CE Power Gain Formula1×
power gain of ce amplifier
Numerical value · 1 shift · 1 numerical
NPN vs PNP Preference and Carrier Mobility1×
assertion-reason on transistor
Assertion–reason · 1 shift
Transistor as a Switch1×
operating regions of transistor as switch
Single correct · 1 shift
Transistor as an Oscillator1×
meaning of feedback in oscillator
Single correct · 1 shift
CE Configuration Characteristics1×
current gain from output characteristics
Numerical value · 1 shift · 1 numerical
CE Amplifier Phase Reversal1×
phase difference in ce amplifier
Single correct · 1 shift

Idea	Times	Shifts	Format	Numerical
CE Amplifier Voltage Gaincurrent gain from power gain in ce amplifier	7	7	Numerical valueCalculation	5
Current Gains Alpha and Betacurrent gain from collector and base change	4	4	Single correctCalculation	–
AC vs DC Current Gainac current gain from output characteristics	2	2	Numerical valueCalculation	1
Transistor Biasing and Structureoperating region of transistor amplifier	2	2	Single correctConceptual	–
CE Power Gain Formulapower gain of ce amplifier	1	1	Numerical valueCalculation	1
NPN vs PNP Preference and Carrier Mobilityassertion-reason on transistor	1	1	Assertion–reasonConceptual	–
Transistor as a Switchoperating regions of transistor as switch	1	1	Single correctRecall	–
Transistor as an Oscillatormeaning of feedback in oscillator	1	1	Single correctConceptual	–
CE Configuration Characteristicscurrent gain from output characteristics	1	1	Numerical valueData or graph	1
CE Amplifier Phase Reversalphase difference in ce amplifier	1	1	Single correctRecall	–

Times and shifts count every analysed shift. Across JEE Main, 78% of questions since 2024 went back to an idea an earlier year had asked; the rest were new. All repeated ideas

Every question

Transistors questions, year by year

The opening words of each question as it appeared in the official paper, with the idea it tested. Open one for its options and the official answer.

Questions from the official JEE Main Paper 1 shifts published by NTA (CBSE for 2017). Questions NTA dropped are left out. Topic and idea tags, counts and notes are Lumi’s.

Key findings

Questions a shift, year by year

Difficulty, format and skill

Difficulty

Format

Skill tested

New idea, or one asked before?

Coverage of the topic

Idea, year, question

Every idea inside this topic

Transistors questions, year by year

JEE Main 20233 questions in 3 shifts

JEE Main 20229 questions in 9 shifts

JEE Main 20217 questions in 6 shifts

JEE Main 20201 question in 1 shift

JEE Main 20171 question in 1 shift

More topics in Semiconductor Electronics: Materials, Devices and Simple Circuits