Question

16. With the help of a diagram, explain the principle 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.

Answer 1

Transformer is the device used to convert high voltage to low voltage or vice versa without violating the law of conservation of energy.

This is made possible by the fact that coils of wires on each side of the transformer have different no. of turns ensuring that the voltage in is different from the voltage out.

The more the number of turns the higher the voltage and this explains why at the input we have High voltage.

At the out put we have fewer number of turns thus low voltage. This process of converting the voltage from low to high and from high to low is know as Stepping up ( for low voltage to high voltage) and stepping down (for high to low voltage).

The transformer is however not 100% efficient because energy is lost in the process of transmitting electricity over long distances.

Answer 2

The device that converts low voltage to a high voltage is the 'Step Up transformer'. The Step Up transformer works on the principle of 'Mutual Inductance'

The Step Up transformer does not violate the Law of conservation of Energy as the output current decreases when there is an increase in the output voltage. The secondary coil has comparatively a more number of turns than the primary coil.

The device has a lot of heat loss due to the Flux leakage and Joule heating. Due to this heating, loss of energy occurs in the copper coils that are present in the primary and secondary coils. The magnetic flux that is generated from the primary coil does not get linked with the secondary coil. So, there is a chance that the efficiency of the device may go down.