Frequency Power Spectra of Global Quantities in Unsteady Magnetoconvection

We present the results of direct numerical simulations power spectral densities for kinetic energy, convective entropy and heat flux unsteady Rayleigh-B\'{e}nard magnetoconvection in frequency space. For larger values frequency, all global quantities vary with $f$ as $f^{-2}$. The scaling exponent is independent Rayleigh number, Chandrasekhar's number thermal Prandtl number.