EMFs, Battery & Resistor: Heat, Work & Energy Loss

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In summary, the cause of heat released in a circuit is related to the resistance (R) and the square of the current (i^2). This energy loss is not caused by the electric field, but rather by the battery mechanism. While textbooks often imply that the resistor is the root cause of heat, according to the free electron theory, it is actually the drifting current electrons colliding with the vibrating metal lattice atoms and transferring energy through these collisions. In a resistive circuit, this is the only form of energy conversion that occurs, as the work done by the battery (emf times charge) is zero.
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atavistic
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When we say heat released in a circuit is i^2 RT , who/what is the cause of this energy loss; is it the battery mechanism? Since work done on charge in the circuit by E field is zero, the only other force seems to be the battery mechanism, right? But in textbooks there is so much implication that the resistor is the root cause of heat, I am confused.
 
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The work done by the battery = emf times charge.The electrons pick up energy in the battery and convert this to other forms of energy in the circuit.If the circuit is resistive only heat is generated.In terms of free electron theory this can be explained in terms of the drifting current electrons continually colliding with the vibrating metal lattice atoms and transferring some of their energy with each collision.
 
  • #3


The heat released in a circuit is a result of energy loss, which is caused by the resistance in the circuit. When an electric current flows through a circuit, it encounters resistance from the components in the circuit, such as the battery and the resistor. This resistance causes some of the electrical energy to be converted into heat energy, which is then released into the surrounding environment.

The formula i^2RT, where i is the current, R is the resistance, and T is the time, is a representation of the amount of heat released in a circuit. This formula is known as Joule's Law and it shows that the amount of heat released is directly proportional to the square of the current, the resistance, and the time.

While the battery plays a crucial role in providing the electrical energy for the circuit, it is not the cause of the energy loss. The battery's mechanism is to convert chemical energy into electrical energy, which is then used to power the circuit. The battery does not directly contribute to the resistance in the circuit, but it does provide the energy that is ultimately lost as heat.

On the other hand, the resistor is specifically designed to create resistance in a circuit. It is made of materials that impede the flow of electrons, which causes a drop in voltage and a conversion of electrical energy into heat. Therefore, the resistor is the primary source of resistance in a circuit and is responsible for the majority of the heat released.

In textbooks, there may be an implication that the resistor is the root cause of heat because it is the component specifically designed to create resistance. However, it is important to understand that both the battery and the resistor play a role in the energy loss in a circuit. Without the battery, there would be no electrical energy to begin with, and without the resistor, there would be no resistance to create the heat. Therefore, it is a combination of both components that leads to the heat released in a circuit.
 

Related to EMFs, Battery & Resistor: Heat, Work & Energy Loss

What are EMFs?

EMFs, or electromagnetic fields, are a type of energy that is created by the movement of electrically charged particles. They can be found in natural sources, such as the Earth's magnetic field, or can be man-made, such as from electronic devices.

How do batteries work?

Batteries work by converting chemical energy into electrical energy. This is done through a chemical reaction that occurs within the battery, creating a flow of electrons from one terminal to the other. This flow of electrons is what powers electronic devices.

What is the relationship between resistors and heat?

When a current flows through a resistor, some of the electrical energy is converted into heat energy. This is due to the resistance of the material in the resistor, which causes the electrons to collide with the atoms and transfer their energy in the form of heat. The amount of heat produced is directly proportional to the resistance of the resistor and the square of the current flowing through it.

What is work in relation to EMFs, batteries, and resistors?

Work is defined as the transfer of energy from one system to another. In the case of EMFs, batteries, and resistors, work is done when energy is transferred from the battery to the resistor, causing it to generate heat. The amount of work done is equal to the amount of energy transferred.

How do energy losses occur in circuits?

Energy losses in circuits can occur due to a variety of factors, such as resistance in wires, conversion of electrical energy into heat energy, and electromagnetic interference. These losses can result in a decrease in the efficiency of the circuit and can also lead to the heating of components, which can affect their performance and lifespan.

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