Скачать или смотреть electrical power and power dissipation in resistors class 12 by hassan fareed

In electrical circuits, power is the rate at which work is done or the rate at which energy is transferred or converted. In the context of resistors, which are common components in electrical circuits, the power and power dissipation can be described using Ohm's Law and the power formula.

Ohm's Law:
Ohm's Law relates voltage (V), current (I), and resistance (R) in a circuit and is given by the equation:

\[V = I \cdot R\]

Power in a Resistor:
The power (P) in a resistor can be calculated using the formula:

\[P = I^2 \cdot R\]

Alternatively, it can be expressed as:

\[P = \frac{V^2}{R}\]

Power Dissipation:
Power dissipation in a resistor refers to the process of converting electrical energy into heat due to the flow of current through the resistor. The power dissipated (P_diss) in a resistor is given by the formula:

\[P_{\text{diss}} = I^2 \cdot R = \frac{V^2}{R}\]

This power dissipation is typically in the form of heat, and it's essential to consider it to ensure that resistors can handle the power they are subjected to without overheating. In many cases, resistors are rated for a certain power (in watts), and it's important to use resistors with power ratings suitable for the application.

Example:
Let's consider a resistor with a resistance of \( R = 10 \, \Omega \) through which a current of \( I = 2 \, \text{A} \) flows. The power dissipated in the resistor would be:

\[ P_{\text{diss}} = I^2 \cdot R = (2 \, \text{A})^2 \cdot (10 \, \Omega) = 40 \, \text{W}\]

Units:
Power is measured in watts (W), where 1 watt is equal to 1 joule per second. So, if a resistor has a power rating of 40 W, it means it can safely dissipate 40 joules of energy per second without overheating.

In summary, understanding power and power dissipation in resistors is crucial for designing circuits and selecting appropriate components to ensure they operate within safe limits. Copyright Disclaimer Under Section 107 of the Copyright Act 1976, allowance is made for 'Fair Use'
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