The distllled water acts as ........ for the electricity.
Write Joule's law of heating.
Draw a schematic diagram of an electric circuit. (in the "on" position) consisting of a battery of five cells of $2\, V$ each, a $5\, \Omega$ resistor, a $8\, \Omega$ resistor, a $12$ $\Omega$ resistor and a plug key, all connected in series. An ammeter is put in the circuit to measure the electric current through the resistors and a voltmeter is connected so as to measure the potential difference across the $12\, \Omega$ resistor.
Calculate the reading shown by the
$(a)$ ammeter $(b)$ voltmeter in the below electric circuit
A $4\, \Omega$ resistance wire is doubled on itself. Calculate the new resistance of the wire.
State which has a higher resistance a $50\, W$ or a $25\, W$ lamp bulb and how many times ?