If $$f=0.5$$ m for a glass lens, what is the power of the lens?
1. $$+0.4$$ D
2. $$+4.0$$ D
3. $$+0.2$$ D
4. $$+2.0$$ D

Subtopic: Â Lenses |
Â 86%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

The radii of curvature of the faces of a double convex lens are $$10$$ cm and $$15$$ cm. Its focal length is $$12$$ cm. What is the refractive index of glass?
1. $$1.3$$
2. $$1.2$$
3. $$1.5$$
4. $$1.4$$

Subtopic: Â Lenses |
Â 81%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

A convex lens has a $$20~\text{cm}$$ focal length in air. What is the focal length in water? (Refractive index of air-water = $$1.33$$, refractive index for air-glass = $$1.5$$)
1. $$+72.72~\text{cm}$$
2. $$+78.2~\text{cm}$$
3. $$-72.72~\text{cm}$$
4. $$+70.2~\text{cm}$$

Subtopic: Â Lenses |
Â 68%
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints

Find the position of the image formed by the lens combination in the given figure.

 1 Final image is formed 30 cm to the right of the third lens. 2 Final image is formed 20 cm to the left of the third lens. 3 Final image is formed 30 cm to the left of the third lens. 4 Final image is formed 20 cm to the right of the third lens.

Subtopic: Â Lenses |
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
What focal length should the reading spectacles have for a person for whom the least distance of distinct vision is $$50~\text{cm}$$?
1. $$-50~\text{cm}$$
2. $$+50~\text{cm}$$
3. $$-60~\text{cm}$$
4. $$+60~\text{cm}$$