Which of the following cannot reduce the terminal voltage of a dc shunt generator?

If the speed of rotation for a four pole, 220V dc machine is 1 m/s, flux density as 2T having length of bore as 0.1m and radius of 0.5m.
The emf induced under pole faces will be

For a four pole, 200 V dc shunt generator having armature resistance of 1 ohms. The current flowing in the armature is 10 A. What is the back emf generated if the terminal voltage of 220 V supply is fed?

A duplex lap wound armature is used in six pole dc machine with six brush set. The number of current paths in this machine is

If the armature current is by mistake increased to 50% for the dc machine,

For a four pole, 16 slot armature with two coil-side/slot having lap connected progressive winding has single turn coils. The same machine is then wave wound, the emf induced in the lap wound dc machine to that of wave wound will be

If the speed of rotation of a separately excited dc machine is halved and the filed strength is also reduced to half of the original. Then the emf induced in the armature

The induced emf in the armature of a 4-pole dc machine is

For a four pole, 16 slot armature with two coil-side/slot having wave connected progressive winding has single turn coils has simplex winding.
The number of current paths

For a 4 pole 200 V, 20 A dc generator running at the rated rpm with no load will be