(1)电阻R1的阻值是多少?电阻R2的总电阻是多少?
(2)当x的值为30 cm时,电流表的示数是多少?
(3)当电压表的示数为4 V时,在20s内电流通过R2产生的热量是多少?
(4)当P移动到最左端E处时,闭合开关S1和S2,电阻R2消耗的电功率与电路消耗的总电功率之比是多少?
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