What is the mathematical expression for Joule's law of the heating effect?

What is the mathematical expression for Joule's law of the heating effect?

• A. P = VI
• B. P = I^2R
• C. P = IR^2
• D. P = V^2/R

Answer: (B)

Joule's law describes the heating effect of electric current flowing through a conductor. The expression given by P = I²R indicates that the power (P) dissipated as heat in a resistor is proportional to the square of the current (I) that flows through it and the resistance (R) of the conductor. This relationship highlights the fact that as the current increases, the power loss due to heat increases with the square of that current, which means small increases in current can lead to significant increases in heating. This equation is derived from the fundamental relationship between voltage, current, and resistance (Ohm's law: V = IR). Substituting Ohm's law into the power equation P = IV (where P is power, I is current, and V is voltage), we can replace V with IR, leading to P = I(IR) = I²R. This shows that the energy converted to heat in a resistor due to electrical energy depends primarily on the current passing through it. Understanding Joule's law is crucial for applications in electrical engineering, as it helps in designing circuits and managing thermal effects in electrical components. The other options do not directly represent Joule's law as they either describe power in different contexts (like using voltage

Joule's law describes the heating effect of electric current flowing through a conductor. The expression given by P = I²R indicates that the power (P) dissipated as heat in a resistor is proportional to the square of the current (I) that flows through it and the resistance (R) of the conductor. This relationship highlights the fact that as the current increases, the power loss due to heat increases with the square of that current, which means small increases in current can lead to significant increases in heating.

This equation is derived from the fundamental relationship between voltage, current, and resistance (Ohm's law: V = IR). Substituting Ohm's law into the power equation P = IV (where P is power, I is current, and V is voltage), we can replace V with IR, leading to P = I(IR) = I²R. This shows that the energy converted to heat in a resistor due to electrical energy depends primarily on the current passing through it.

Understanding Joule's law is crucial for applications in electrical engineering, as it helps in designing circuits and managing thermal effects in electrical components. The other options do not directly represent Joule's law as they either describe power in different contexts (like using voltage