Physics - Magnetism Question with Solution | TestHub

In the$\text{xy - plane}$, the region$y>0$has a uniform magnetic field$B_1\widehat{k}$and the region$y<0$has another uniform magnetic field$B_2\widehat{k}$. A positively charged particle is projected from the origin along the positive$\text{y}-\text{axis}$with speed$v_0=\mathrm{\pi }\mathrm{m}{\mathrm{ s}}^{-1}$at$t=0$, as shown in the figure. Neglect gravity in this problem. Let$t=T$be the time when the particle crosses the$\text{x}-\text{axis}$from below for the first time. If$B_2=4B_1$, the average speed of the particle, in$\mathrm{m}{\mathrm{ s}}^{-1}$, along the$\text{x}-\text{axis}$in the time interval$T$is ________.