Write an expression for the heat produced when an electric current is passed through it.

Explanation

To derive the expression for the heat produced when an electric current is passed through a conductor, we can follow these steps:

### Step 1: Understand Joule's Law
Joule's Law states that the heat (H) produced in a conductor when an electric current (I) passes through it is directly proportional to the square of the current, the resistance (R) of the conductor, and the time (t) for which the current flows.

### Step 2: Write the Basic Formula
From Joule's Law, we can express the heat produced as:
\[ H \propto I^2 \cdot R \cdot t \]
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