Electric power is the electrical work done per unit time.

FORMULA:

Power=Work done /Time taken

P=W/t

The substances through which electricity can flow are called conductors.

Eg: Aluminium , silver , copper etc.

Nichole,Manganin,Constantan

Those substances through which electric charges cannot flow are called insulators.

Eg: Glass, Ebonite, Rubber, Cotton, Mica, Porcelain etc.

The electric potential at a point in an electric field is defined as the work done in moving a unit positive charge frome infinity to that point.

The potential difference between two points in an electric circuit is defined as the amount of work done in moving a unit positive charge to the other point.

FORMULA:

Potential difference =Workdone/Quantity of charge moved

P=W/Q

The SI unit of potential difference is volt

Rheostat

Ohm's law gives the relationship between current potential difference.

At constant temperature, the current flowing through the conductor is directly proportional to the potential difference across its ends.

The ratio of potential difference applied between the ends of a conductor and the current flowing through it is a constant quantity called resistance

Ohm metre

NICHROME alloy is used to make electrical appliances such as Room heaters, Electrical kettles, Water heater, Toasters etc.

> NICHROME has very high resistivity.

>It does not undergo oxidation easily (or burn) easily even at high temperatures.

>if one electrical appliance stops the others keep working .

>each electrical appliance has its own switch, due to which they can be turned on or off independently.

>the overall resistance of the household circuit is reduced due to which the current from the power supply is high.

Watt

When an electric current is passed through a high resistance wire the resistance wire becomes very hot and produces heat. This is called Heating effect of Electric current.