∵W=1kW?h,P=40W=0.04KW,∴t= W P = 1kW?h 0.04KW =25h,又∵U=220V,P=40W,∴灯泡的电阻值为:R= U2 P = (220V)2 40W =1210Ω,而U实=110V,∴灯泡的实际功率为:P实= U实2 R = (110V)2 1210Ω =10W.故答案为:25,10.