Dimensions of ${ϵ}_0\frac{d{\varphi }_{ϵ}}{dt}$ are same as that of (symbols have their usual meanings) _________

Assertion : In an e.m. wave magnitude of magnetic field vector $\overrightarrow{B}$ is much smaller than the magnitude of vector $\overrightarrow{E}.$

Reason : This is because in an e.m. wave $\frac{E}{B}=c=3\times {10}^8 \mathrm{m} {\mathrm{s}}^{-1}.$