Your question is not clear.
There is no such thing as a 'resultant' three-phase voltage. There are three, separate, line voltages (i.e. voltages measured between line conductors) for a delta-connected supply, which are equal in magnitude to the corresponding phase voltages. For a balanced wye-connected system, there are three line-voltages (again, measured between line conductors) which are 1.732 larger than the three phase-voltages (measured between each line conductor and the neutral conductor). For an unearthed unbalanced three-phase wye-connected load (unusual, but possible), the figure of 1.732 doesn't apply; instead the relationship must be determined by vector addition.
If your question means to ask how do you determine the line voltages of a wye-connected system, given a set of unbalanced phase voltages, then you must vectorially add the relevant phase voltages to determine the relevant line voltage, taking into account the sense, or direction, of each phase voltage.
If two phase voltages are the same voltage and the same phase angle, the the resultant voltage will be twice the voltage.
The voltages appearing across each branch of a parallel circuit will be equal to the supply voltage.
The unit of resistance is the Ohm, and by applying a small voltage to your wire, and measuring the resultant current, you may calculate the resistance.From the formula I = E/R, where R = resistance in Ohms, E is the voltage in volts, and I is the current in amperes.
you calculate a voltage circuit by taking it apart and findng the circuit and calculate the voltage and then resible it.
formals to calculate exciation voltage of alternator
Voltage drop is resultant of IR ie current and the line resistance, not dependent on impressed emf
Secondary voltage / primary voltage
To calculate an answer a voltage must be stated.
Since the alternators are in parallel, the resultant voltage should be the same as either alternator - exactly as it would be if two batteries are connected in parallel. Voltage remains the same but current capacity is doubled. I would recommend connecting the alternators through a network that will balance the load between them.
How do you calculate voltage drop for starting motor current
no load voltage - full load voltage by full load voltage
Not enough information. Power = current x voltage. Since voltage can be anything, there is no way to calculate power. Time is irrelevant; though once you have the power, it can help you calculate energy (energy = power x time).