Correct Answer - Option 4 : 1.2

**Concept:**

Emf induced in a DC generator is directly proportional to Flux per pole and the rotor speed i.e.

E ∝ ϕ ⋅ ω

or. E = K_{a} ϕ ⋅ ω

Where K_{a} = Proportionality constant \(=\frac{ZP}{2\pi A}\)

Where, Z = No. of conductors

P = No. of Poles

A = No. of Parallel paths

ϕ = Flux per pole

ω = Angular velocity in rad/sec

Converting it in rotation per minute,

\(\omega = \frac{2\pi N}{60}\)

By Putting the above values in EMF equation, we will get

\(E=\frac{ϕ ZN}{60}\times \frac{P}{A}\)

**Calculation:**

Given,

P = 4, N = 650 rpm

E = 200 V, Z = 750

A = 2, ϕ = 0.015 wb

\(E = \frac{\phi Z N}{60}\times \frac{P}{A}\)

\(E=\frac{0.015 \times 750 \times 650}{60} \times \frac{4}{2}\)

E = 243.75 V

Given, generation rating of convertor is 200.

But it is generating 243.75 V

Hence, leakage coefficient \(=\frac{243.75}{200}\)

= 1.21875

Hence, correct option will be option (4)

No. of parallel paths in wave wound machine = 2

No. of parallel paths in lap wound machine = No. of poles i.e. A = P