1) Explain how will you reverse the polarity of collected E.M.F at brushes of the dc generator?
2) Specify the different parts of the DC machine. Specify function of commutator in the dc machine?
3) Explain the phenomenon behind why does the speed of motor dip upon loading?
4) A 250V dc machine has an armature resistance of 0.25?. If full load armature current is of 40A, determine the induced E.M.F when the machine acts as the motor.
5) A single phase 3000/220V, 50Hz, core type transformer has the square cross section of 0.2 m side. If maximum flux density in core is 1.0T. Determine the number of turns in the HV and LV winding.
6) When the secondary of a transformer is open, why does a primary current flow? Explain in detail.
7) Provide the expression of current when two transformers of unequal voltages are linked in parallel.
8) Explain what is meant by the CT? Provide some of its applications.
9) Write down the EMF equation of the PMBL DC motor and describe each parameter.
10) Provide the application of tachogenerators.