A separately excited $$d.c.$$ motor has an armature resistance of $$0.5$$ $$ohm.$$ It runs off a $$250$$ $$V$$ $$d.c.$$ supply drawing an armature current of $$20$$ $$A$$ at $$1,500$$ $$rpm.$$ The torque developed for an armature current of $$10$$ $$A$$ will be __________ for the same field current.

Two transformers of the same type, using the same grade of iron and conductor materials, are designed to work at the same flux and current densities; but the linear dimensions of one are two times those of the other in all respects. The ratio of $$kVA$$ of the two transformers closely equals

An electrostatic potential is given by $$\phi=2x\sqrt y$$ volt in the rectangular co-ordinate system. The magnitude of the electric field at x = 1 m,y = 1 m is _________V/m

Which of the following equations represents the Gauss's law in a homogeneous isotropic medium?