公式E =ΔΔt 与E =Blvsinθ的联系和区别公式E =ΔΔt,是感应电动势的定义式 ,ΔΔt是磁通量的变化率 ,即磁通量变化的快慢程度。严格地讲 ,这个公式对一切电磁感应现象都适用 ,既能用来求某一时刻 (或某一位置 )感应电动势的瞬时值 ,又能用来求某段时间Δt内感应电动势 The relationship between the formula E = ΔΔt and E = Blvsinθ and the difference formula E = ΔΔt is the definition formula of the induced electromotive force, ΔΔt is the change rate of the magnetic flux, that is, how fast the magnetic flux changes. Strictly speaking, this formula is applicable to all electromagnetic induction phenomena. It can be used not only to determine the instantaneous value of the induced electromotive force at a certain moment (or a certain position), but also to find the induced electromotive force during a certain period of time Δt.