Question

I have a question for the effect and difference on a DC motor for the speed( rad/s) in time (sec) if you apply:

1. Nothing (so no charge in the circuit only the mecanic charge of the generator)

2. A resistant charge (only the resistant is plug in with the generator)

3. Short circuit (No exterior electric charge but the terminals are bounds together so an excessive amount of current flow into the circuit)

4. Capacitive charge (only the capacitor is plug in with the generator)

I would like to know a simple explaination of every result to know why it does that compared to the others please.

Answer 1

The question is not clear but anyway I assume that the DC motor is rotated using some external work and used as a generator.
1)Whe no load is given the speed of the motor will be maximum.
2)When a resistor is applied to the motor the speed will reduce according to the value of resistor, ie as the resistance increases the speed increases and reaches maximum speed when resistance is infinite which is similar to 1st case is no load condition.
3)When the circuit is short circuited the speed will reduce suddenly and motor will stop or the windings of motor will burn out.
4)When a capacitor is applied the capacitor will start charging. at the time of connecting capacitor the speed of motor reduces and a time goes capacitor get charged while speed will increase and finally the capacitor get fully charged and speed will reach to its maximum speed similar to no load.