Urgent Help needed in PHYSICS ATP !!!!

[TheMasterMind]

guys kindly anyone help me to solve Q 4b of may/june 2010 atp
tomoro is paper plz fast!!!!http://www.xtremepapers.me/CIE/Cambridge O Levels/5054 - Physics/5054_s10_qp_42.pdf

 

[mrrul3z]

he observes the pins from th other side of the glass. when the pins P1 and P2 are seen to be in line then th student places two other pins P3 and P4, in the same line on other side of the paper.
did that help?

 

[TheMasterMind]

no man .....can u plz explain it simply......kindly solve the whole question on that diagram n paste it here ....
Diagram wud b a gr8 hrlp plz!!!

 

[ravaneous]

well here is the simple explanation

first draw the incident line
than observe the marked line from the other side of the plastic circle
mark the pins p3 and p4 where you see the lines on the other side

I think its simple enough

 

[floral123]

well here is the simple explanation

first draw the incident line
than observe the marked line from the other side of the plastic circle
mark the pins p3 and p4 where you see the lines on the other side

I think its simple enough

yups this is the answer!