In the figure, a very large plane sheet of positive charge is shown. \( P_1 \) and \( P_2 \) are two points at distance \( l \) and \( 2l \) from the charge distribution. If \( \sigma \) is the surface charge density, then the magnitude of electric fields \( E_1 \) and \( E_2 \) at \( P_1 \) and \( P_2 \) respectively are:
