SSC CGL Physics · Free notes

Light and Optics: SSC CGL Physics

Light and Optics has 11 questions in the SSC CGL Tier I bank: one from the 2023 shifts and five each from the 2024 and 2025 shifts. They ask one fact each: a mirror's use, a lens's power, what refraction leaves unchanged, or how the eye adjusts. One page gathers them in two tables.

The handout has every subtopic, worked example, formula and trap with answers shown. The formula sheet is the chapter’s formulas and traps alone, on one page.

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Subtopic notes

Mirrors, Lenses and Refraction
11 PYQs
Concave mirrors, ray diagrams and lens power, what stays the same when light is refracted, the eye's near point and pupil, diffraction, gamma rays and the secondary rainbow.

Formula & revision sheet

0 formulas · 2 reference tables · 2 gotchas across all subtopics — the exam-eve cheat-sheet

Mirrors, Lenses and Refraction

Reference tables (2)

Mirrors and lenses3 rows

Point	Fact
Solar furnace mirror	ConcaveQ
Rays to find an image	TwoQ
Object at focus of convex lens	Image at infinityQ

Refraction, the eye and light's behaviour6 rows

Point	Fact
Law of refraction	SnelliusQ
Near point of the eye	25 cmQ
Pupil size controlled by	The irisQ
Bending round small obstacles	DiffractionQ
Shortest wavelength	Gamma raysQ
Secondary rainbow	Colours reversedQ

Watch out for (2)

Biconvex is a lens
→ Mirrors and lenses
The iris, not the cornea
→ Refraction, the eye and light's behaviour

PYQ weightage by concept

2 concepts · 11 PYQs — where the marks actually sit, so you know what to drill first

Mirrors, Lenses and Refraction11 PYQs · 100%

Concept	PYQs	Share
Refraction, the eye and light's behaviour	7	64%
Mirrors and lenses	4	36%

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