Silicon is $......$

Draw a circuit diagram for a circuit consisting of a battery of five cells of $2$ volts each, a $5\, \Omega,$ resistor, a $10\, \Omega$ resistor and a $15 \,\Omega$ resistor, an ammeter and a plug key; all connected in series. Also, connect a voltmeter to record the potential difference across the $15\, \Omega$ resistor and calculate

$(i)$ the electric current passing through the above circuit and

$(ii)$ potential difference across $5\, \Omega$ resistor when the key is closed.

Why is heat produced when a current is passed through a conductor ?

State the factors on which the resistance of a cylindrical conductor depends, How will resistance of a conductor change if it is stretched so that its length is doubled ?

How will you infer with the help of an experiment that the same current flows through every part of the circuit containing three resistances in series connected to a battery?

Which particles are responsible for the flow of current in conductors ?