Question

State and explain Joule's Law and of heating derive H=12 Rt.

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Answer 1

Statement:-

There are mainly three points by which we can explain Joule's Law:-

• Heat in an electric circuit is directly proportional to the square of Current $\tt (I^2)$ in the circuit.

• Heat in an electric circuit is directly proportional to the Resistance (R) in the circuit.

• Heat in an electric current is directly proportional to the Time (T) at which the current is passed through the circuit.

Derivation:-

$\\ \tt\mapsto E = PT.$

Where,

• E = Energy i.e. Heat.

• P = Power Generate by flowing by current.

• T = Time.

Also we know that,

$\\ \tt\mapsto P = VI.$

Where,

• V = Potential Difference.

• I = Current.

Also,

$\\ \tt\mapsto V = IR.$

$\\ \tt\mapsto P = VI.$

$\\ \tt\mapsto P = I^2R.$

Therefore,

$\\ \large\red{\mapsto\boxed{\blue{\bf H = PT = I^2RT.}}}$