Generator
To increase the strength of magnetic field around a) current carrying conductor
Increase the current through it
To increase the strength of magnetic field around a) current carrying solenoid
pass more current, increase the number of turns of the coil
Split ring commutator IS USED TO
To reverse the direction of current in every half cycle so that the rotation of the coil will be continuous.
Transformer - parts
Primary and secondary coils - must be good conductor (copper)
Core - must be soft magnetic material (Iron)
what is Electromagnetic induction
Whenever the magnetic field lines are cut by a conductor, current will be induced in the conductor.
Law of magnetism
Like poles will repel and unlike poles attract
What is a solenoid
A coil of copper wire, can be used to make electromagnet
define magnetic field
it is the space around a magnet where a magnetic material experiences a force.
If you have it, you want to share it. If you share it, you don’t have it. What is it?
A secret
I’m not alive, but I can grow; I don’t have lungs, but I need air; I don’t have a mouth, but water kills me. What am I?
fire
Working of transformer:
ac will be given in the primary, it creates a changing magnetic field. It will be transmitted to the secondary through the iron core. And secondary coils cut this magnetic field and induce an emf. Depending on the number of turns it will be either stepped up or down.
Why electricity transmitted at high voltage
High voltage means low current, when transmit at low current, energy loss as heat will be less. Also we can use thinner cables for transmission.
Method to magnetise
Stroke with a magnet, keep in the magnetic field (N/S direction) abd hit,keep in the solenoid and pass dc
Methods to demagnetise
Hit (E/W direction), heat or pass ac and slowly withdraw the magnet