A focal length of a lens is 10 cm. What is the power of a lens in dioptre?

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Solution

Step 1: Given data
Focal length of lens( $f$ )= $10 c m = 0.1 m$
Step 2: Formula used and calculation
To find the Power of the lens in Diopter
Power $P = \frac{1}{f (i n m e t e r s)} = \frac{1}{0.1} = 10 m^{- 1}$
Power of lens is represented in Diopter
1D = $\frac{1}{1 m o f f o c a l l e n g t h} = 1 m^{- 1}$
$1 D = 1 m^{- 1} 10 m^{- 1} = 10 D$
Therefore the power of the lens is 10D

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A focal length of a lens is 10 cm. What is the power of a lens in dioptre?

Step 1: Given dataFocal length of lens(f)=10cm=0.1mStep 2: Formula used and calculationTo find the Power of the lens in DiopterPower P=1f(inmeters)=10.1=10m-1Power of lens is represented in Diopter 1D = 11moffocallength=1m-11D=1m-110m-1=10DTherefore the power of the lens is 10D