Calculation of EMF Generated on Open Circuit

Given parameters:
- Number of poles (p) = 8
- Number of conductors (N) = 960
- Flux per pole (ϕ) = 40 Wb/pole
- Speed (N) = 400 rpm

Formula to calculate EMF generated on open circuit:
EMF = 2 * N * ϕ * p / 60

Substituting the values in the above formula,
EMF = 2 * 400 * 40 * 8 / 60
EMF = 4266.67 V

Therefore, the EMF generated on open circuit is 4266.67 V.

Calculation of Speed Required to Generate 400 V on Wave Connection

Given parameters:
- Number of poles (p) = 8
- Number of conductors (N) = 960
- Flux per pole (ϕ) = 40 Wb/pole
- EMF (E) = 400 V
- Connection type = Wave

Formula to calculate speed required to generate 400 V on wave connection:
E = 4.44 * N * ϕ * p * f

where f = frequency of induced emf

As the armature is wave connected, the number of circuits (C) is 2.
Therefore, the number of parallel paths (A) is 1.

Formula to calculate frequency of induced emf:
f = A * N * Ns / 120 * C

Substituting the values in the above formula,
f = 1 * 960 * 400 / 120 * 2
f = 160 Hz

Substituting the values in the first formula,
400 = 4.44 * 960 * 40 * 8 * 160
400 = 14745600.00

The above equation is not possible to solve as the left-hand side is 400 and the right-hand side is a very large number. Therefore, the speed required to generate 400 V on wave connection cannot be calculated with the given parameters.

Explanation

- Given parameters such as the number of poles, number of conductors, flux per pole, and speed are used to calculate the EMF generated on open circuit using a formula.
- The connection type is given as wave and the EMF is given as 400 V. The speed required to generate this EMF on wave connection is calculated using two formulas. One formula is used to calculate the frequency of the induced emf and the other formula is used to calculate the speed required. The number of parallel paths is taken as 1 as the armature is wave connected.
- The final result cannot be obtained as the equation cannot be solved with the given parameters.

256v, 156.25