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

Zero
Small
generator, the induced e.m.f. at zero speed will be A. Zero B. Small C. The same as rated voltage
High

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.

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