A point object kept at P in front of a glass sphere of radius ' R ' has its image formed at Q such that PO = QO. The refractive index of material of glass sphere is 1.4. The distance PO is equal to (a) R/2 (b) 2R (c) 5R (d) 6R

Answer: (d). Refraction at the first surface: μ/v - 1/u = (μ - 1)/(R) with u = -x, v = +x (Q inside the sphere). 1.4/x + 1/x = 0.4/R 2.4/x = 0.4/R ⇒ x = 6R So the answer is (d) 6R.

A point object kept at P in front of a glass sphere of radius ' R '… | MHT CET 2024 (9 May, Shift 1)

Q48MHT CET 2024 · 9 MAY · SHIFT 1Difficult

Spherical Surfaces & Thin Lenses

A point object kept at P in front of a glass sphere of radius ' $R$ ' has its image formed at $Q$ such that $\text{PO} = \text{QO}$ . The refractive index of material of glass sphere is 1.4. The distance PO is equal to

Show answer and solution

Answer: (d)

Refraction at the first surface: $\frac{\mu}{v} - \frac{1}{u} = \frac{\mu - 1}{R}$ with $u = -x$ , $v = +x$ (Q inside the sphere).
$\frac{1.4}{x} + \frac{1}{x} = \frac{0.4}{R}$
$\frac{2.4}{x} = \frac{0.4}{R} \Rightarrow x = 6R$
So the answer is (d) $6R$ .

Report a mistake

Spherical Surfaces & Thin Lenses question from MHT CET 2024 (9 May, Shift 1)

More questions on Spherical Surfaces & Thin Lenses