The frame of electric motor is connected to three plates having earthing resistance of 10 Ω, 20 Ω and 30 Ω respectively. The materials of the three plates are copper, aluminium and iron respectively. The percentage of energy dissipated by 10 Ω earthing plate

• A. is more than 50% of total energy
• B. is less than 50% of total energy
• C. depends on the materials of the three plates
• D. may be more or less than 50% of total energy