壶的容积 | 1.5L |
额定电压 | 220V |
加热功率 | 1000W |
保温功率 | 44W |

(1)当开关S1闭合,S2_____(填“闭合”或“断开”)时,养生壶处于加热状态.
(2)在保温档正常工作时,求电路中的电流是________?
(3)求R1、R2的阻值___,___欧.
(4)如果养生壶的效率为70%,那么在标准大气压下要将满壶的水从20℃加热至沸腾,请问需要_____分钟?

同类型试题

y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2


y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2

