Power Dissipated in Moving the Conductor #8211; For uniform motion of rod PQ, power delivered by external source is given as P<sub>mech</sub> = P<sub>ext</sub> = dW/dt = F<sub>ext</sub>times;v = B<sup>2</sup>vl<sup>2</sup>/Rtimes;v ⇒ [P<sub>mech</sub> = B<sup>2</sup> v<sup>2</sup> l<sup>2</sup>/R Also, electrical power dissipated in resistance or rate of heat dissipation across resistance is given as P<sub>thermal</sub> = H/t = I<sup>2</sup> R = (Bvl/R)<sup>2</sup>times;R; P<sub>thermal</sub> = B<sup>2</sup> v<sup>2</sup> l<sup>2</sup>/R