Job Recruitment Website - Zhaopincom - (20 14? Huizhou simulation) The heater used at home, the voltage used in normal operation is alternating current which changes according to the sinusoidal law in the figure, and the heater works norma

(20 14? Huizhou simulation) The heater used at home, the voltage used in normal operation is alternating current which changes according to the sinusoidal law in the figure, and the heater works norma

(20 14? Huizhou simulation) The heater used at home, the voltage used in normal operation is alternating current which changes according to the sinusoidal law in the figure, and the heater works normally. A, from the relationship between the maximum value of sinusoidal alternating current and the effective value, U = 3 1 12V = 220V, so a is correct.

B, according to the image, the period of alternating current is 0.02s, so B is wrong.

C, the circular frequency ω = 2π t = 100π, g, so the expression of alternating current is u = 311sin100t (v), so c is wrong.

D, from P=UI=220×3W=660W, so D is correct.

Therefore: ad.