how can we find focal length of lens?
Answers
Answered by
0
The focal length of the lens an be found out experimentally by any of the following two methods.
1..Distant object method
2. u- v method
1..Distant object method
2. u- v method
Answered by
1
Focal length of lens can be found by the formula:-
1/f=(n-1) x 1/R
For example:-
If the radius of curvature of the curved face of a thin plano-convex lens is 10 cm and it is made of glass of refractive Index 1.5.
Then:-
1/f=(n-1) x 1/R
Here n=1.5 & R =10
So:-
1/f =(1.5-1)x1/10
Or 1/f=0.5/10
Or 1/f=5/100=1/20
Hence f= 20 cm
This is the easiest way to calculate focal length of a lens.
Hope it will be helpful to understand in easiest way.
Similar questions