JEE Main 2024 (Online) 6th April Evening Shift | Geometrical Optics Question 5 | Physics

For the thin convex lens, the radii of curvature are at $$15 \mathrm{~cm}$$ and $$30 \mathrm{~cm}$$ respectively. The focal length the lens is $$20 \mathrm{~cm}$$. The refractive index of the material is :

1.2

1.5

1.4

1.8

JEE Main 2024 (Online) 4th April Morning Shift

MCQ (Single Correct Answer)

-1

An effective power of a combination of 5 identical convex lenses which are kept in contact along the principal axis is $$25 \mathrm{D}$$. Focal length of each of the convex lens is:

50 cm

20 cm

25 cm

500 cm

JEE Main 2024 (Online) 4th April Morning Shift

MCQ (Single Correct Answer)

-1

In an experiment to measure focal length ($$f$$) of convex lens, the least counts of the measuring scales for the position of object (u) and for the position of image (v) are $$\Delta u$$ and $$\Delta v$$, respectively. The error in the measurement of the focal length of the convex lens will be:

$$2 f\left[\frac{\Delta \mathrm{u}}{\mathrm{u}}+\frac{\Delta \mathrm{v}}{\mathrm{v}}\right]$$

$$f\left[\frac{\Delta \mathrm{u}}{\mathrm{u}}+\frac{\Delta \mathrm{v}}{\mathrm{v}}\right]$$

$$f^2\left[\frac{\Delta \mathrm{u}}{\mathrm{u}^2}+\frac{\Delta \mathrm{v}}{\mathrm{v}^2}\right]$$

$$\frac{\Delta \mathrm{u}}{\mathrm{u}}+\frac{\Delta \mathrm{v}}{\mathrm{v}}$$

JEE Main 2024 (Online) 31st January Morning Shift

MCQ (Single Correct Answer)

-1

The refractive index of a prism with apex angle $$A$$ is $$\cot A / 2$$. The angle of minimum deviation is :

$$\delta_m=180^{\circ}-3 \mathrm{~A}$$

$$\delta_m=180^{\circ}-4 A$$

$$\delta_m=180^{\circ}-2 A$$

$$\delta_m=180^{\circ}-A$$