B) Write lenz's law as electromagnetre induction.
(4) What is transformer ? What do you mean by
its elticiency a
Answers
Lenz’s law lays down the rule to find the direction of induced current (or polarity of induced emf). It states that the induced current will be in such a direction as to oppose the change that caused it. If you push the north pole of a bar magnet into a coil of wire, it will produce a current in the coil (assuming the circuit is closed). This current will produce a magnetic field in the coil. This field will oppose the north pole coming into the coil. In other words, it will produce a north pole in that end of the coil. If you pull out the north pole from inside the coil, then the current will be in the opposite direction, producing a south pole so as to attract the north pole that is moving away.
To find the type of pole created in a coil, look into coil from an end. If you see the current circling in anticlockwise direction, then it is a north pole; clockwise direction indicates a south pole. (Just imagine that the letters N and S have arrow marks on both ends. Then the arrows point in the direction of current around the coil!)
Explanation:
Transformer is an electromagnetic device ,which is used to either step up or step down the voltage levels by keeping power,frequency and flux as constant.
there are many types of transformers based on their level of usage
1.Power Transfomers
2.Distribution Transformers
3.Instrument Transformers