Transformers

 Transformer- is made of coils, is quite hefty for it's size. The coils increase or decrease the voltage according to it's specifications. Transformers are rated in VA (volt-ampere). This is not the same as a watt, which is normally what is used to rate your appliances.

• Step- Up Transformer:  it is a transformer used to raise voltage output from a power plant generator for a long- distance transmission. 
• Step- Down Transformer: it is a transformer with a less loops in the secondary than that in the primary. 

What are the appliances that Uses transformer?

 The appliances that uses transformer are radios, CD players, shavers, battery rechargers, computer printers, fax machines, televisions, answering machines, and fluorescent lamps. 

Relate the voltage and current in the primary and secondary coils to the numbers of turn in each: 

 The current in the primary coil has to keep on changing with time for current in the secondary coil to be induced. Thus in alternating current in the primary is ideal, although pulsating DC may be used. In alternating current in the primary coil, a continues induced current which is also an alternating one, is drawn from the secondary coil. While the induced voltage in a generator depends on the number of loops in the armature. The induced voltage in the secondary coil depends on its number of loops. If greater induced voltage is desired, then there should be fewer loops. The ratio of voltage in the primary coil to the induced voltage in the secondary coil equals the ratio of the number of loops in the primary coil to that in the secondary coil.