一根长度为L的铜棒,在均匀磁场<img src="https://tihai-oss-cloud.itihey.com/img/a9bc57d991636f3cc7de2f9be964b061.gif">中以匀角速度ω旋转着,<img src="https://tihai-oss-cloud.itihey.com/img/a9bc57d991636f3cc7de2f9be964b061.gif">的方向垂直铜棒转动的平面,如图.设t=0时,铜棒与Ob成θ角,则在任一时刻t这根铜棒两端之间的感应电动势是: <img src="https://tihai-oss-cloud.itihey.com/img/c88072979174bbb933100563da979b5e.png">