1ok bro. i m trying
a parallel beam of light enters a clear plastic bead 2.5 cm in diameter and index 1.4. at what point beyond the bead are these rays brought to a focus ????
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17 Answers
62conventions will not change the answer..
And a suggestion:
If you have not figured out a convention yet, I wud advice you to follow the absolute frame of reference convention.
62you have to apply the lensmaker's formula twice.
once on the first surface.. then on the second surface...
First v that you calculate will be substraced by 2.5 mm.. to get the u for the second surface.
24is the answer 35/8 cm ??????????
here is the solution....read it only if ans is correct..otherwise u will get confused..[3]
applying lens maker formula :
1.4/v -1/∞ =0.4/(2.5/2) becoz R =diameter/2=0.25/2
=>v=35/8 cm
62i think we need to use the lensmaker's formula with the approximatin that if the beam is very thin then it converges!
or you could directly use the refraction formula μsinθ= constant.
and use the first principle to find the same!
1even m confused abhirup i [7] i am sorry i dun know though i wud try again
13is this focal point independent of the distance betn the two beams??[7]