Two metallic plates P and Q of equal surface area are heated to the same temperature. Plate P is coated with dull black paint having emissivity 0.9, while plate Q is polished and has emissivity 0.3. Which one of the following statements is correct regarding their thermal radiation power?
a) Plate P radiates one-third as much power as plate Q.
b) Plate P and plate Q radiate equal power.
c) Plate P radiates three times as much power as plate Q.
d) Plate P radiates nine times as much power as plate Q.