JEE Main · Chemistry · The Solid State
Solid State Defects: JEE Main previous year questions
9 questions in the 108 JEE Main shifts Lumi analysed, in 4 of 8 years. Pattern: Comes in cycles. 2 came in 2024–26. Here is how it is asked and which ideas come back.
- Questions
- 9
- in 9 of 108 shifts
- Years asked
- 4/8
- last asked 2024
- Weighted estimate
- 0.0
- model; history: 0.0 a shift on average, typically 0.0–0.1
Key findings
- 01
Asked in 4 of 8 years with analysed shifts and in 9 of 108 shifts: 9 questions, #183 of 196 topics. The years that asked it were 1.3 apart on average. Last asked in 2024.
- 02
100% of its questions since 2020 tested an idea no earlier year had asked; none repeated an idea from the year before.
- 03
The most repeated idea is Band Theory of Solids, asked 2 times in 2 shifts (2024), most often as “count conductors from conductivity data”.
- 04
JEE Main has asked 7 of the 55 ideas in this topic; 42 have never been asked, directly or inside another question.
- 05
Mostly asked as numerical value (33%); 33% need a numerical answer, 56% are easy and 0% hard.
- 06
The skill tested most is recall (44%), then calculation (22%).
Questions a shift, year by year
Out of the 25 Chemistry questions in a shift. Years differ in how many shifts Lumi analysed, so each year is scaled to one shift.
Raw count: 2017: 0 in 1 shift · 2020: 1 in 12 shifts · 2021: 4 in 24 shifts · 2022: 2 in 24 shifts · 2023: 0 in 12 shifts · 2024: 2 in 18 shifts · 2025: 0 in 8 shifts · 2026: 0 in 9 shifts.
- Up to 2023
- 0.1
- a shift, of 25
- Since 2024
- 0.0
- 0.0
- Usual gap
- 1.3 yrs
- between years asking it
- Shifts with it
- 9/108
- 8% of analysed shifts
How it is asked
Difficulty, format and skill
Across all 9 questions on Solid State Defects since 2017.
Difficulty
QUESTIONS- Easy5 · 56%
- Medium4 · 44%
- Hard0 · 0%
Format
SHARE- Numerical value · 3 Q33%
- Single correct · 3 Q33%
- Match the list · 2 Q22%
- Two statements · 1 Q11%
Skill tested
SHARE- Recall · 4 Q44%
- Calculation · 2 Q22%
- Conceptual · 2 Q22%
- Data or graph · 1 Q11%
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.
- Idea asked for the first time
- Idea asked in an earlier year
Coverage of the topic
JEE Main has asked 7 of the 55 ideas in this topic. 42 have never been asked yet.
- Asked directly7 · 13%
- Touched inside another question6 · 11%
- Never asked42 · 76%
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.
- 6 Apr ’24 S1 · Q64Which of the following material is not a semiconductor.
easySingle correctNew idea
- 31 Jan ’24 S2 · Q84The values of conductivity of some materials at 298.15 K in Sm are , , ,…
mediumNumerical valueNew idea
- 6 Apr ’24 S1 · Q64
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
7 different ideas were tested; 2 came more than once.
count conductors from conductivity data
Numerical value · 2 shifts · 1 numericalstatement i/ii on solid state defects
Match the list · 2 shiftspercentage of fe2+ in fe0.93o
Numerical value · 1 shift · 1 numericalincorrect statement on imperfections in solids
Single correct · 1 shiftcation vacancies from aliovalent doping
Numerical value · 1 shift · 1 numericalmatch list on magnetic properties and examples
Match the list · 1 shiftcompound showing frenkel and schottky defects
Single correct · 1 shift
| Idea | Years asked | Times | Shifts | Format | Numerical |
|---|---|---|---|---|---|
| Band Theory of Solidscount conductors from conductivity data | 2 | 2 | Numerical valueData or graph | 1 | |
| Frenkel Defectstatement i/ii on solid state defects | 2 | 2 | Match the listConceptual | – | |
| Non-Stoichiometric Composition Calculationspercentage of fe2+ in fe0.93o | 1 | 1 | Numerical valueCalculation | 1 | |
| Schottky Defectincorrect statement on imperfections in solids | 1 | 1 | Single correctConceptual | – | |
| Impurity Defects and Dopingcation vacancies from aliovalent doping | 1 | 1 | Numerical valueCalculation | 1 | |
| Magnetic Propertiesmatch list on magnetic properties and examples | 1 | 1 | Match the listRecall | – | |
| AgBr Dual Defect Exceptioncompound showing frenkel and schottky defects | 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
Solid State Defects 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.
JEE Main 20242 questions in 2 shifts
- 6 Apr, Shift 1Q64Which of the following material is not a semiconductor.
Idea: Band Theory of Solids
New ideaEasySingle correct - 31 Jan, Shift 2Q84The values of conductivity of some materials at 298.15 K in Sm are , , ,…
Idea: Band Theory of Solids
New ideaMediumNumerical value
JEE Main 20222 questions in 2 shifts
- 27 Jun, Shift 1Q81Metal deficiency defect is shown by . In the crystal, some cations are missing and loss of…
Idea: Non-Stoichiometric Composition Calculations
New ideaMediumNumerical value - 28 Jun, Shift 1Q61The incorrect statement about the imperfections in solids is :
Idea: Schottky Defect
New ideaEasySingle correct
JEE Main 20214 questions in 4 shifts
- 4 Aug, Shift 1Q31Match List I with List II List I List II A. Frenkel defect I. CsCl B. Schottky defect II. Pink LiCl C. Impurity defect III. ZnS D. Metal…
Idea: Frenkel Defect
New ideaMediumMatch the list - 26 Aug, Shift 1Q31Given below are two statements : Statement I : Frenkel defects are vacancy as well as interstitial defects. Statement II : Frenkel defect…
Idea: Frenkel Defect
New ideaEasyTwo statements - 27 Aug, Shift 1Q32Match items of List - I with those of List - II : List - I (Property) List - II (Example) (a) Diamagnetism (i) MnO (b) Ferrimagnetism (ii)…
Idea: Magnetic Properties
New ideaEasyMatch the list - 17 Mar, Shift 2Q52KBr is doped with mole percent of . The number of cationic vacancies in 1 g of KBr crystal is…
Idea: Impurity Defects and Doping
New ideaMediumNumerical value
JEE Main 20201 question in 1 shift
- 8 Jan, Shift 2Q31Which of the following compounds is likely to show both Frenkel and Schottky defects in its crystalline form ?
Idea: AgBr Dual Defect Exception
New ideaEasySingle correct
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.