A DC generator works on the principle of Faraday`s laws of electromagnetic induction. This principle states that when a conductor is moved through a magnetic field or when there is a change in the magnetic field lines passing through a conductor, an electromotive force (EMF) is induced in the conductor.

In the case of a DC generator, a coil of wire is rotated within a magnetic field. As the coil cuts through the magnetic field, the flux linking the coil changes, which induces an EMF in the coil. This generated EMF causes a current to flow in the coil and creates a potential difference between the terminals of the generator, resulting in the generation of Direct Current (DC).

Option 1, Ohm`s law, is not the correct answer as Ohm`s law relates current, voltage, and resistance in a circuit, and it does not directly explain the working principle of a DC generator.

Option 2, Joule`s law of heating, is also not the correct answer as this law relates to the heat generated in a conductor due to the flow of electric current, and it does not explain the working principle of a DC generator.

Option 4, None of the above, is not the correct answer since the correct explanation for a DC generator is provided in