A doctor has prescribed a corrective lens of power, -1.5D. Find the focal length of the lens. Is the prescribed lens diverging or converging?
Download our app for free and get started
$\text{P}=-1.5\text{D}$$\text{P}=\frac{1}{\text{f}}$
$\text{f}=\frac{1}{\text{P}}=\frac{1}{(-0.5)}=-0.66\text{m}=-66.6\text{m}$
Since focal length is negative, it is a diverging lens.
$\text{f}=\frac{1}{\text{P}}=\frac{1}{(-0.5)}=-0.66\text{m}=-66.6\text{m}$
Since focal length is negative, it is a diverging lens.
Download our appand get started for free
Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*
Similar Questions
- 1View SolutionExplain why, a real image can be projected on a screen but a virtual image cannot.
- 2View SolutionIf a ray of light is incident on a plane mirror such that it makes an angle of 30with the mirror, then will be the angle of reflection?
- 3View SolutionWrite down the magnification formula for a lens in terms of object distance and image distance. How does this magnification formula for a lens differ from the corresponding formula for a mirror?
- 4View SolutionAn object is placed just outside the principal focus of concave mirror. Draw a ray diagram to show how the image is formed, and describe its size, position and nature.
- 5View SolutionDraw a ray diagram to show the path of the reflected ray corresponding to an incident ray which is directed towards the principal focus of a convex. mirror. Mark on it the angle of incidence and the angle of reflection.
- 6View SolutionIf two lenses (convex) are in contact with each other, what happens to the ray after refraction?
- 7AB and CD, two spherical mirrors, form parts of a hollow spherical ball with its centre at O as shown in the diagram. If arc $\text{AB}=\frac{1}{2}$ arc CD, what is the ratio of their focal lengths? State which of the two mirrors will always form virtual image of an object placed in front of it and why.View Solution
- 8View SolutionA 5cm tall object is placed perpendicular to the principal axis of a convex lens of focal length 18cm at a distance of 12cm from it. Use lens formula to determine the position, size and nature to the image formed.
- 9View SolutionWith the help of a ray diagram, determine the position, nature and size of the image formed of an object placed at the centre of curvature of a concave mirror.
- 10View SolutionWhich lens would you prefer to use while reading small letters from a dictionary?