✓ 3 MARKS
Derivations
🔥 APPEARED IN 3 BOARD SETS
(a) Draw a labelled ray diagram showing the formation of an image by an astronomical refracting telescope in normal adjustment. Hence, obtain the expression for its magnifying power.
OR
(b) A plane wavefront of light of wavelength '$\lambda$' is incident normally on a narrow slit of width 'a' and a diffraction pattern is observed on a screen at a distance 'D' from the slit.
(i) Depict the intensity distribution in the pattern observed.
(ii) Obtain the expression for the first maximum from the central maximum.
01 // VERIFIED BOARD OCCURRENCES
| Year | Paper Code | Set | Position |
|---|---|---|---|
| CBSE 2022 | Series 55-2 | Set 1 | Question 6 |
| CBSE 2022 | Series 55-2 | Set 2 | Question 8 |
| CBSE 2022 | Series 55-2 | Set 3 | Question 9 |
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)