A solid iron sphere of radius=1m is just submerged in a water tank. A point source of light is kept vertically above its center at a distance 1m from the water surface.
Find the area of the sphere's shadow. Refractive index of water=1.414.
Here's a Hint
remind me for another good light problem.
ReplyDelete7.16 mtr sq
ReplyDelete7.567 mtr sq?
ReplyDeleteThis problem does not require that you have studied opticks in your JEE preparation.
ReplyDeletesin(i)/sin(r)=refractive index.
I guess everyone knows this.
Then its a maths problem.
i could find it in terms of i and r-
ReplyDeletepi* (2tan r+cot(i+r))^2 ?
From the diagram: 2*i+r=90
ReplyDelete25.4 m^2 ?
ReplyDeletehow is 90-i = i+r in hint.. i m askin dis bcoz gettin answer in terms of iand r...
ReplyDeletesorry, but the 'thing' in terms of 'i' and 'r' is not an 'answer'.
ReplyDeleteanyway:
angle b/w green line and maroon line: i
angle b/w maroon line and horizontal: i+r
angle b/w green line and horizontal: 90
hence: (i)+(i+r)=90.
@rajesh-
ReplyDeletei+r=90-i
sin i/sin r=1.414
2 equations ,2variables
4.71?
ReplyDeleteThis comment has been removed by the author.
ReplyDeleteThis comment has been removed by the author.
ReplyDeletewel..i can see the hint.. i just want to ask dat angle btw maroon line and horizontal = i +r is given or can we can prove it by geometry.?
ReplyDeletemy ans. followin d hint is cuming 4.46?