well, now I can talk about physics paper 6 without breaking any rule (it's been over 24 hs since I sit for it)... the question is how do you measure the thinkness of a lens using two wooden blocks??
I answered that you need to measure the thikness of both wooden blocks, and then place them block-lens-block; the blocks parallel to each other and touching the lens by each side. Then measure the thickenss of all the three things together (block-lens-block) and to this measurement substract the initial thickness of both blocks.
Is this right??
Sorry if the description is not very clear; but I draw a diagram in the exam (that's what the question asked for) .
Thanks!