STATE JOULE'S LAW OF HEAT.

 Joule's law of heating implies that heat produced in a resistor is:

directly proportional to square of current flowing in resistor i.e. HI²

directly proportional to resistancefor a given current i.e. HR

directly proprtional to timefor which the current flows i.e. HT

So, H=I²RT.

 Joule's laws are a pair of laws concerning the heat produced by a current and the energy dependence of an ideal gas to that of pressure, volume, and temperature, respectively. They are named after James Prescott Joule.
Joule's first law, also known as the Joule effect, is a physical law expressing the relationship between the heat generated by the current flowing through a conductor. Joule studied this phenomenon in the 1840s. It is expressed as:

where is the heat generated by a constant current flowing through a conductor of electrical resistance , for a time . When current, resistance and time are expressed in amperes, ohms, and seconds respectively, the unit of is the joule. Joule's first law is sometimes called the Joule–Lenz law since it was later independently discovered by Heinrich Lenz. The heating effect of conductors carrying currents is known as Joule heating.
Joule's second law states that the internal energy of an ideal gas is independent of its volume and pressure, depending only on its temperature.

 When a current of I amperes passes through a circuit of resistance R ohms for a time of t seconds then the heat produced is given by the relation.

H=I²Rt joules The above relation is known as the joule’s law of heating. It states that the heat produced is proportional to

1.Square of the current I.

2.Resistance of the circuit R.

3.The time t during which the current flows through the circuit.

Heat produced in calories can be expressed as                 H=I²Rt/4.18 calories (1 calorie=4.18 joule)