论文部分内容阅读
例1如图1所示,竖直平面内有足够长的金属导轨,轨距0·2m,金属导体ab可在导轨上无摩擦地上下滑动,ab的电阻为0·4Ω,导轨电阻不计,导轨ab的质量为0·2g,垂直纸面向里的匀强磁场的磁感应强度为0·2T,且磁场区域足够大,当ab导体自由下落0·4s时,突然接通开关S,则:(1)试说出S接通后
Example 1 As shown in Figure 1, the vertical plane has a long enough metal guide rail, track gauge 0.2 m, the metal conductor ab can slide up and down on the rail without friction, ab the resistance of 0 · 4Ω, The mass of the guide rail ab is 0.2 g, the magnetic induction intensity of the uniform magnetic field perpendicular to the plane of the paper is 0.2 T, and the magnetic field area is large enough. When the ab conductor freely falls for 0 · 4 s, the switch S is suddenly turned on: (:( 1) After trying out S is connected