This depends on whether the voltage is AC or DC but an oscilloscope is the tool of choice for seeing voltages and how they change with time.
For AC motor, you can change motor RPM by changing its supply voltage or by changing supply frequency. For DC motor, you can change motor speed by controlling armatyre voltage or field current.
A basic electrical circuit needs a voltage supply (battery or household outlet), wiring to carry electrons to and from the voltage supply to the load, and a load (motor, light, heat element, stereo, blender, whatever).
You can't. You must supply the motor with it's required voltage. If it's a dual voltage motor, follow the wiring schematic on the motor nameplate to switch from low to high voltage.
In principle a generator is the same as a motor. In a dc motor the voltage generated by the rotating armature is slightly less than the supply voltage which causes power to flow in from the supply. If an engine is then coupled to the shaft causing it to rotate faster, then it generates more voltage and power flows back into the supply. That is how a motor becomes a generator.
To answer this question the motor's voltage must be stated and whether the supply voltage is single phase or three phase.
The voltage tag on a motor says 120 or 220 volt and some motors have jumpers to wire it for either one. That is the supply line voltage. The motor knows how to use that. If the plate says three phase is required then consult your electic supply Company for a three phase supply line.
Shorting the motor's electrical supply will blow the fuse and the motor will run down and stop.
No, not directly. The supply voltage has to rise or the resistance has to fall to get over-current. If there was a secondary control voltage that was part of a voltage control circuit for a higher voltage, it is conceivable that a voltage drop in control circuit could cause an over-voltage in the supply. Motors are constant power devices, so this could be true for a motor. If you have a 1hp motor (loaded at 1hp), it will want to draw 1hp of power no matter the supply voltage. If the voltage dips, the motor will require more current to keep it spinning at it's normal speed.
For an electrical load, such as a lamp, heater or motor, to operate at its rated power, it must be subject to its rated voltage which always corresponds to the supply voltage. For this to happen, individual loads must be connected in parallel with the supply and with each other. So all the electrical loads in your home, in your car, etc., are ALL connected in parallel.
In the electrical trade it is called control voltage. This voltage can be any voltage. In North America the common control voltage is 120 volts.
The phase voltage is usually constant and determined by the supply voltage.
The current depends on the supply voltage.