(2)小华在连接电路时,闭合开关前滑动变阻器滑片应移到
A.更换小灯泡 B.移动滑动变阻器滑片
C.检查开关是否接触不良 D.检查电压表是否断路
(3)当电压表的示数为2.5V时,电流表示数如图乙所示,则小灯泡的额定功率为
(4)实验前张老师在实验室测得小灯泡正常发光的功率比铭牌上标定的功率要小一些,张老师猜想可能该灯泡灯丝长度比标准的
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