解?$:(1)I_{額}=\frac {P_{額}}{U_{額}}=\frac {9\ \mathrm {W}}{220\ \mathrm {V}}≈0.04\ \mathrm {A}$?
?$(2)W_{LED}=P_{LED}t=9×10^{-3}\ \mathrm {kW}×10\ \mathrm {h}=0.09\ \mathrm {kW·h}$?
?$W_{白熾燈}=P_{白熾燈}t=60×10^{-3}\ \mathrm {kW}×10\ \mathrm {h}=0.6\ \mathrm {kW·h}$?
?$W_{差}=W_{白熾燈}-W_{LED}=0.6\ \mathrm {kW·h}-0.09\ \mathrm {kW·h}=0.51\ \mathrm {kW·h}$?