With the help of a diagram, explain the priciple of a device which changes a low voltage into a high voltage but does not violate the law of conservation of energy. Give any one reason why the device may not be 100% efficient.
Device : Transformer (1/2) marks
Diagram on page number 260 NCERT part (1) marks
Principal: statement of mutual induction (1) marks
Efficiency : Assuming no energy losses, the transformer is 100% efficienty i.e.