If residual magnetism is present in a D.C. generator, the induced e.m.f. at zero speed will be

The correct answer is: B. Small

Residual magnetism is the magnetism that remains in a ferromagnetic material after it has been subjected to a magnetic field. It is caused by the alignment

of the magnetic domains in the material. When a DC generator is turned on, the residual magnetism causes a small current to flow in the armature windings. This current creates a magnetic field that opposes the residual magnetism. The result is that the induced EMF at zero speed is small.

Option A is incorrect because the induced EMF at zero speed is not zero.

Option C is incorrect because the induced EMF at zero speed is not the same as the rated voltage.

Option D is incorrect because the induced EMF at zero speed is not high.