# Power of a lens

Write a program to determine the power of a lens .
Power of a lens is its ability to bend light . For a convex lens, the converging ability is defined by power and in a concave lens, the diverging ability . The diopter ( D ) is the unit of measuring power of a lens .
The power is defined as the reciprocal of the focal length in meters .

D = ( 1 / F )
Here, D is the power in diopter,
F is the focal length in meters.

Examples:

```Input : F = 2
Output : D = 0.5

Input : F = 0.2
Output : D = 5
```

## C++

 `// C++ program to determine ` `// the power of a lens ` `#include ` `using` `namespace` `std; ` ` `  `// function to determine the  ` `// power of a lens ` `float` `power(``float` `focal_length) ` `{ ` `    ``return` `(1 / focal_length); ` `} ` ` `  `// driver function ` `int` `main() ` `{ ` `    ``float` `focal_length = 2; ` `    ``cout << ``"The power of the lens in diopter is "` `         ``<< power(focal_length); ` `     `  `    ``return` `0; ` `} `

## Java

 `// Java program to determine ` `// the power of a lens ` `import` `java.io.*; ` ` `  `class` `GFG  ` `{ ` `    ``// function to determine the  ` `    ``// power of a lens ` `    ``static` `float` `power(``float` `focal_length) ` `    ``{ ` `        ``return` `(``1` `/ focal_length); ` `    ``} ` `     `  `    ``// Driver code  ` `    ``public` `static` `void` `main (String[] args)  ` `    ``{ ` `        ``float` `focal_length = ``2``; ` `        ``System.out.println(``"The power of the lens in diopter is "` `                           ``+ power(focal_length)); ` `         `  `    ``} ` `} ` ` `  `// This code is contributed by Gitanjali. `

## Python3

 `# Python3 program to determine ` `# the power of a lens ` ` `  `# function to determine ` `# the power of a lens ` `def` `power( focal_length ) : ` ` `  `    ``return` `( ``1` `/` `focal_length ) ` ` `  `# driver function ` `focal_length ``=` `2` `; ` `print` `( ``"The power of the lens in diopter is "``, end ``=` `"") ` `print` `(power(focal_length) ) `

## C#

 `// C# program to determine ` `// the power of a lens ` `using` `System; ` ` `  `class` `GFG  ` `{ ` `    ``// function to determine the  ` `    ``// power of a lens ` `    ``static` `float` `power(``float` `focal_length) ` `    ``{ ` `        ``return` `(1 / focal_length); ` `    ``} ` `     `  `    ``// Driver code  ` `    ``public` `static` `void` `Main ()  ` `    ``{ ` `        ``float` `focal_length = 2; ` `        ``Console.WriteLine(``"The power of the lens in diopter is "` `                        ``+ power(focal_length)); ` `         `  `    ``} ` `} ` ` `  `// This code is contributed by vt_m. `

## PHP

 ` `

Output:

``` The power of the lens in diopter is 0.5
```

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