Time of onset: In Jamaica, it begins one to 2 hours after death and takes further one to 2 hours to develop. In temperate countries, it begins in 3 to 6 hours and takes further 2 to 3 hours to develop. Duration of rigor mortis: In Jamaica, usually it lasts 18 to 24 hours in winter and 12 to 18 hours in summer.
Then by either moving the wire or changing the magnetic field we can induce a voltage and current within the coil and this process is known as Electromagnetic Induction and is the basic principal of operation of transformers, motors and generators.he changing magnetic flux in the iron core of a transformer above will induce an emf, not only in the primary and secondary windings, but also in the iron core. The iron core is a good conductor, so the currents induced in a solid iron core will be large.
A variable autotransformer is a single-coil transformer in which two portions of the same coil are used as the primary and the secondary. Variable autotransformers are used for the same purposes as regular transformers, but handle lower voltages.ariable autotransformers consist of a regular autotransformer that has been scratched in order to expose part of the coil, a sliding brush, and any automatic switches that a particular Variac requires.