How to make a magnet

Actually electromagnet are temporary magnet.it is not a permanent magnet.it works when the elctricity pass through them.we can make a simple magnet.need things to magnet are 1.cell(using pencil cell or 9vcell or other) 2.metal(like iron etc)3.insulator wire or copper wire 4.one switch (optional)
Use a large wire connect the wire one side to the cell and the other end of wire wind the metal or coiling the metal.the remaing wire connect to the switch(not available connect to the cell directly)turn one cell wait few second the magnet ready to attract any metal object.increasing of the coil or wind yo the metal to increasing the attraction force

How to make a radio station

We can easy make radio circuit but we know about. How to simple radio broadcast station.simple broadcast station require components are capacitor,inductor,resistor etc.the inductor is signal send act as a tower and the capacitor is act as a sound booster and circuit current booster.we connect a mic to the circuit and speak when the circuit works the inductor send signals to the real FM station but the signal range is low at 30m radius.

Transformer

Transformer is electric device which boost electricity.when we will connect the input to transformer and high electricity than input electricity and reduce electricity than input mostly use stepdown transformer is used reduce electricity than input normally used in TV ,ampilifer etc

Speaker

Speaker is a device used in many electronic circuit.the speaker is produce sound that hear by our ears.speaker is used in TV,mobile etc.we connect the audio to the speaker and produce audio .how does it work.when the audio signal connected to the speaker.inside the speaker vibrating and produce sound why vibrating.inside the speaker has coil it is made up of copper.the coil transform to magnetic field when the audio signal gets the coil respond to the backside magnetic and vibration made and produce sound. The high volume connected to a speaker produce sound and distortion because the coil will heavy vibrating