A.图1中炉外有线圈,线圈中通以反复变化的电流,利用涡流产生的热量使金属熔化 |
B.图2中为了减少涡流,利用相互绝缘的硅钢片叠成的铁芯来代替整块硅钢铁芯 |
C.图3中探雷器遇见金属时,金属会感应出涡流,涡流的磁场反过来影响线圈中的电流,使仪器报警 |
D.图4中两个磁性很强的小圆柱形永磁体同时从铝管上端管口落入,无论铝管有无裂缝,它们同时从铝管下端管口落出 |
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