If you are on a personal connection, like at home, you can run an anti-virus scan on your device to make sure it is not infected with malware. The power of a lens is specified as P = $\frac{1}{F}$, where f is the focal length. Completing the CAPTCHA proves you are a human and gives you temporary access to the web property. Another way to prevent getting this page in the future is to use Privacy Pass. Performance & security by Cloudflare, Please complete the security check to access. unit of power of a lens is $m^{-1}$. • The focal length (f) of a converging lens is considered positive and that of a diverging lens is considered negative. Power - definition Power of a lens is defined as the inverse of focal length (in meters) of the lens. Determine the focal length of the lens. Your IP: 109.123.75.40 Cloudflare Ray ID: 5f8f9b0bdee2dc27 If you are at an office or shared network, you can ask the network administrator to run a scan across the network looking for misconfigured or infected devices. Power of a Lens. Remember. • Solution: From the graph, when v = u, the coordinate of the point of intersection is given as (2f, 2f), where f is the focal length of the lens. The shorter the focal length, the greater the power. Power of lens calculation. Power of a lens is –40, its focal length is (a) 4 m (b) – 40 cm (c) – 0.25 m (d) – 25 m. Login. Figure shows a graph of v against u. The power for a convex lens is positive and the power for a concave lens is negative. 2f = 30 … P = f 1 Note: Convex lens has positive power and concave lens has negative power. This is also known as diopter. Power of lens and its unit. Diopter formula. The S.I. You may need to download version 2.0 now from the Chrome Web Store. It is a measure of the amount of deviation of light ray produced by a lens, more the power, more is the deviation. Lens Equation Problems and Solutions. Optical power. Unit of power is Dioptre (D).