Thermal instability of magnetoconvection in a horizontal bidispersive
porous layer, uniformly heated from below, is analyzed. To study the
linear stability theory, we perturbed the basic state with
small-amplitude disturbances. Then, the governing dimensionless
equations are solved using the normal modes. By employing the one-term
Galerkin weighted residuals method, the critical values of Rayleigh
numbers for the onset of stationary and oscillatory instability, have
been determined. The effect of Chandrasekhar number on the system was
analyzed.