A user has four 40W fluorescent lamps, 140W TV and audio equipment, 120W refrigerator, and an 800W rice cooker. Question: (1) is it appropriate for the user to use the "220V, 5A" energy meter, and why? (2) The electricity charge of the residential area is 0.5 yuan / kW · h. if these electrical appliances are used less than half an hour a day on average, how much money can be saved in one month (30 days)?

A user has four 40W fluorescent lamps, 140W TV and audio equipment, 120W refrigerator, and an 800W rice cooker. Question: (1) is it appropriate for the user to use the "220V, 5A" energy meter, and why? (2) The electricity charge of the residential area is 0.5 yuan / kW · h. if these electrical appliances are used less than half an hour a day on average, how much money can be saved in one month (30 days)?

(1) Maximum power: P = UI = 220V × 5A = 1100W, P = P1 + P2 + P3 + P4 = 40W × 4 + 140W + 120W + 800W = 1220w. Because 1220w ＞ 1100W, it is not suitable for the user to use the "220V, 5A" energy meter. (2) the energy saved: w = P ′ t = 1.22kw × 0.5h × 30 = 18.3kw · h. then the electricity saved is: 18.3kw · h × 0.5 yuan / kW · H = 9.15 yuan (2) a month (30 days) can save 9.15 yuan