there are infinite wires each having resistance R joined like a net. Plz tell what will be the eq resistance between any 2 adjacent pts A and B.

PLz explain..

 

 

see, by snell's law r=45 degrees

no we knoW  that    sin=cnstt

so  sin(i)=[of air] sinr

diff with respect to time

cos(i)*di/dt=[ of air]cos(r)*dr/dt

now, di/dt is . and dr/dt we have to find.

so putting in the values

WE will get dr/dt (ans) as 1/sqrt2.