✓ 3 MARKS
Short Answer
🔥 APPEARED IN 3 BOARD SETS
(a) Draw the energy-band diagrams for conductors, semiconductors and insulators at $\text{T} = 0\text{ K}$. How is an electron-hole pair formed in a semiconductor at room temperature ?
(b) Carbon and silicon both, are members of \text{IV} group of periodic table and have the same lattice structure. Carbon is an insulator whereas silicon is a semiconductor. Explain.
01 // VERIFIED BOARD OCCURRENCES
| Year | Paper Code | Set | Position |
|---|---|---|---|
| CBSE 2025 | Series 55-5 | Set 1 | Question 22 |
| CBSE 2025 | Series 55-5 | Set 2 | Question 23 |
| CBSE 2025 | Series 55-5 | Set 3 | Question 27 |
02 // OFFICIAL CBSE MARKING SCHEME BREAKDOWN
- Step 1: Stating the fundamental formula / law statement (+1 Mark)
- Step 2: Intermediate mathematical substitution or proof steps (+1 Mark)
- Step 3: Correct final value or conclusion with mandatory SI units (+1 Mark)