The low voltage winding of a $$400/230V,$$ $$1$$-phase, $$50$$ $$Hz$$ transformer is to be connected to a $$25$$ $$Hz,$$ the supply voltage should be

A $$200V$$, $$10$$ $$kW$$ lap-wound $$d.c.$$ generator has $$10$$ poles and $$500$$ conductors on it's armature. If the pole face covers $$80\% $$ of the pole pitch, the pole face conductors required to fully compensate for armature reaction will be ___________________ conductors/pole.

Determine the electric field intensity at the point $$P$$ for the arrangement shown in Fig.

A square coil of $$10$$ turns and $$10$$ $$cm$$ side is moved through a steady magnetic field of $$1$$ $$Wb/{m^2}$$ at a constant velocity of $$2$$ $$m/sec$$ with its plane perpendicular to the field as shown in Fig. Plot the variation of induced $$e.m.f$$ as the coil moves along the field.