✓ 2 MARKS
Numericals
🔥 APPEARED IN 3 BOARD SETS
(b) In a Young's double-slit experiment, fringes are obtained on a screen placed at a distance $D$ from the slits. It is observed that if the screen is moved $5\text{ cm}$ towards the slits, the fringe width changes by $0.03\text{ mm}$. If the distance between the slits is $1\text{ mm}$, calculate the wavelength of the light used.
01 // VERIFIED BOARD OCCURRENCES
| Year | Paper Code | Set | Position |
|---|---|---|---|
| CBSE 2026 | Series 55-7 | Set 1 | Question (b) |
| CBSE 2026 | Series 55-7 | Set 2 | Question 32 |
| CBSE 2026 | Series 55-7 | Set 3 | Question 31 |
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)