Correct Answer - Option 2 : 21 kV

__Concept:__

A DC generator is an electrical machine whose main function is to convert mechanical energy into electricity. When the conductor cuts magnetic flux, an emf will be generated based on the electromagnetic induction principle of Faraday’s Laws. This electromotive force can cause a flow of current when the conductor circuit is closed.

The emf equation of the DC generator is given by the equation:

\({E_g} = \frac{{PNϕ Z}}{{60A}}\)

where

Z = Total number of armature conductor

P = The number of poles in a generator

A = The number of parallel paths

N = Speed of armature in r.p.m

ϕ = Flux per pole

**Lap winding **

**A = P**

Wave winding

A = 2

__Explanation: __

Given

P = 6

Z = 150

N = 1200 rpm

ϕ = 7 Wb/pole

Lap winding

A = P = 6

\({E_g} = \frac{{PNϕ Z}}{{60A}}\)

\({E_g} = \frac{{6 × 1200 × 150 × 7}}{{60 × 6}}\)

Eg = 21,000 V = 21 kV