The magnetic field reaches its maximum value, $B_{\text{m}\text{a}\text{x}}=8\mathrm{.}3{10}^{-6}T,$ in the z direction at some point and at some instant. Express the magnitude of the electric field at this position and time, $E_{\text{m}\text{a}\text{x}},$ in terms of $B_{\text{m}\text{a}\text{x}}.$