How to determine heat from resistance?

In summary, there is a formula that can determine the thermal energy released from electricity flowing through a wire, based on the wire's resistance. This formula is derived logically using the equation for work done and the relationship between voltage, charge, and work. The formula is: Thermal energy released from wire due to its heating = k I2 T l/a, where I is the current, R is the resistance, T is the time, a is the area of cross section, and k is the resistivity of the wire.
  • #1
Thundagere
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Is there a formula of some sorts that can determine the thermal energy released from electricity flowing through a wire, knowing the wire's resistance?
 
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  • #2
Thundagere said:
Is there a formula of some sorts that can determine the thermal energy released from electricity flowing through a wire, knowing the wire's resistance?

Yes , there is formula. You can even derive it logically. You can do it! Work done=Energy manifested is a basic logical equation in fundamental physics.

Thermal energy released from wire due to its heating = I2RT
Thermal energy is not released from electricity. It is released due to resistance in a wire because work is done on per unit charge to move it through certain displacement in a wire. On moving a unit charge it faces obstruction or friction of wire. This work done is manifested in form of heat energy in a wire.

You know ,
V=W/Q
W=VQ
So Heat energy released or work done by wire :
Thermal energy released from wire due to its heating = VQ
Thermal energy released from wire due to its heating = IR x IT
Thermal energy released from wire due to its heating = I2RT

Where I is current flowing in wire , R is resistance and T is time.

R=k l/a
a is area of cross section in a wire and l is length of wire.
k is (rho) or resistivity in a wire.

Thermal energy released from wire due to its heating = k I2 T l/a
 

1. How does resistance affect heat?

Resistance is a measure of how difficult it is for electricity to flow through a material. When there is resistance in a circuit, some of the energy is converted into heat. The higher the resistance, the more heat will be generated.

2. Can I use Ohm's Law to determine heat from resistance?

Yes, Ohm's Law states that the amount of current flowing through a circuit is directly proportional to the voltage and inversely proportional to the resistance. By rearranging the equation to solve for power (P = VI), we can determine the amount of heat generated from a given resistance.

3. How do I measure the resistance of a material?

To measure resistance, you will need a multimeter. Set the multimeter to the resistance (ohms) setting and touch the two probes to opposite ends of the material. The multimeter will display the resistance in ohms.

4. What factors can affect the resistance of a material?

The resistance of a material can be affected by its length, cross-sectional area, and temperature. Longer materials will have higher resistance, while materials with larger cross-sectional areas will have lower resistance. Temperature can also impact resistance, as some materials have higher resistance at higher temperatures.

5. How does temperature affect the heat generated from resistance?

As mentioned earlier, temperature can impact the resistance of a material. This means that as the temperature of a material increases, its resistance also increases, leading to more heat being generated. This is why some electronic devices have built-in cooling systems to prevent overheating and potential damage due to increased resistance and heat.

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