A step down transformer connected to an ac mains

Transformer equations - Higher The ratio of potential differences on the transformer coils matches the ratio of the numbers of turns on the coils. This equation can be used to calculate what the output might be from a particular transformer, or to work out how to design a transformer to make a particular voltage change: \[\frac\] voltage from secondary coil, \(V_s = 12~V\) The transformer in the example above is a step-down transformer. This is because there are fewer turns on the secondary coil, and there is a smaller voltage on the secondary coil.

Concept: If there are no power losses in the transformer than it is known as Ideal transformer. In an ideal transformer, input power is always equal to output power. Calculation: Given: V p= 220 V Vs = 11 V Power of lamp, P = 44W In ideal transformer: Input power = Output power ⇒ V pl p= V sl s= Given power ⇒ 220× l p= 44 ⇒ l p = 0.2 A