If the secondary is open there is no power drawn from the power source. But there is current in the primary. The current in the primary is the cause and result of the buildup and collapsing of the magnetic field in the primary (it is self perpetuating).noobish said:something i read from the textbook and i don't understand.
"in an ideal transformer, no magnetizing current is required to produce the flux"
so, where does the flux come from?
An ideal transformer is a device that transfers electrical energy from one circuit to another through electromagnetic induction. It consists of two coils of wire, a primary and secondary, wrapped around a shared iron core. When an alternating current is applied to the primary coil, it creates a changing magnetic field which induces a voltage in the secondary coil, resulting in an electrical current.
The flux in an ideal transformer is created by the alternating current flowing through the primary coil. As the current changes direction, it creates a changing magnetic field, which passes through the iron core and induces a voltage in the secondary coil.
The ratio of the number of turns in the primary and secondary coils is equal to the ratio of the input and output voltages of an ideal transformer. This is known as the turns ratio and is represented by the equation Vp/Vs = Np/Ns, where Vp is the primary voltage, Vs is the secondary voltage, Np is the number of turns in the primary coil, and Ns is the number of turns in the secondary coil.
Yes, an ideal transformer can have a turns ratio greater than 1. This is known as a step-up transformer, where the secondary voltage is higher than the primary voltage. Step-up transformers are commonly used in power distribution systems to increase the voltage for long-distance transmission, reducing energy losses.
Yes, there are several practical limitations to ideal transformers. These include losses due to resistance in the coils and the core, leakage flux, and saturation of the core material. These limitations result in a less than perfect transfer of energy between the primary and secondary coils, making real-world transformers less efficient than ideal ones.