another olympiad question

i am not able to understand the figure clearly

ok whatever i hv understood ,
w=2Ï€f

ans i) i hv given the expression as at time t

C₁²V₀²cos²wt/(2Ï€a²Îµ0)

time average of sin²Î¸=1-time avg.cos²Î¸=1/2

hence final expression =
C₁²V₀²/(4Ï€a²Îµ0)

ans ii)

μ₀C₂²V₀²w²b/2h

iii)speed of light expression =

(C₂wa/C₁)*√(2Ï€b/h)

iv) just put and calculate!

well done thats right