question_answer

A horizontal telegraph wire 10m long oriented along the magnetic east-west direction, falls freely under gravity to the ground from a height of 10 m. Find the emf (in volt) induced in the wire at the instant the wire strikes ground. \[({{B}_{H}}= 2.5 \times  1{{0}^{-}}^{5}Wb/{{m}^{2}}, g = 9.8 m/{{s}^{2}})\]

Answer:

\[\operatorname{e}={{B}_{H}}\ell \,v=\,\,2.5\times {{10}^{-5}}\times 10\times 14=3.5\times {{10}^{-\,3}}\,volt\]