How Transformers Work: Explaining Ohm's Law

In summary, Ohm's law states that the flow of electricity through a conductor is directly proportional to the potential difference, but transformers seem to be an exception to this law. However, transformers do not violate Ohm's law and their behavior can be explained by the number of turns in the windings. A step up transformer induces a larger voltage from the primary coil to the secondary coil, causing a decrease in electron flow. This is because the primary coil has a relatively lower voltage but a higher flow of electrons, while the secondary coil has the opposite. To understand this further, it is recommended to research on transformers and how they work.
  • #1
Ahmed Abdullah
203
3
Ohm's law states that at constant temperature the flow of electricity through a conductor is proportion to the potential difference across the conductor. But It always appeared to me that transformers are indifferent to this law. Here, how it is.
A step up transformer induce larger voltage from the primary coil to secondary coil. But the electron flow falls. Primary coil has relatively lower voltage but higher flow of electrons. The secondary coil has vice versa. Does it violate Ohm's law (V=IR)?
Please help.
 
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  • #2
Transformers don't violate Ohm's law. Google on transformer and see why they act the way they do, and pay attention to the way the number of turns in the windings affect the voltage and current flow.
 
  • #3


I can provide an explanation for how transformers work and how they do not violate Ohm's Law. Ohm's Law states that the flow of electricity, or current (I), is directly proportional to the voltage (V) and inversely proportional to the resistance (R) of a conductor. This means that as voltage increases, current also increases, and as resistance increases, current decreases.

In a transformer, the primary coil is connected to a power source and the secondary coil is connected to a load. The primary coil has a certain number of turns and the secondary coil has a different number of turns. When an alternating current flows through the primary coil, it creates a changing magnetic field. This changing magnetic field induces a voltage in the secondary coil, based on the ratio of turns between the two coils.

Now, let's consider Ohm's Law in this scenario. The voltage in the primary coil is determined by the power source, and the current is determined by the resistance of the primary coil. In the secondary coil, the voltage is induced by the changing magnetic field and the current is determined by the resistance of the secondary coil. So, while the voltage and current may have different values in the primary and secondary coils, Ohm's Law still holds true for each individual coil.

In other words, Ohm's Law is not violated in a transformer because it is still valid for each individual coil. The step up transformer you mentioned is simply changing the voltage and current values without changing the fundamental relationship between them.

I hope this explanation helps to clarify how transformers work and how they are not indifferent to Ohm's Law. If you have any further questions, please do not hesitate to ask.
 

Related to How Transformers Work: Explaining Ohm's Law

1. What is Ohm's Law and how does it relate to transformers?

Ohm's Law is a fundamental principle of electricity that states the relationship between voltage (V), current (I), and resistance (R). It can be expressed as V=IR, where V is the voltage, I is the current, and R is the resistance. In the context of transformers, Ohm's Law explains how the input voltage and current are related to the output voltage and current.

2. How do transformers use Ohm's Law to step up or step down voltage?

Transformers use the principle of electromagnetic induction to change the voltage of an alternating current (AC). When an AC current flows through the primary coil of a transformer, it creates a changing magnetic field. This magnetic field induces a current in the secondary coil, which results in a different voltage depending on the number of turns in each coil. Ohm's Law helps to determine the ratio of the input and output voltages.

3. What is the significance of the turns ratio in transformers?

The turns ratio is the ratio of the number of turns in the primary coil to the number of turns in the secondary coil. It plays a crucial role in determining the output voltage of a transformer. According to Ohm's Law, if the turns ratio is high, the output voltage will be higher than the input voltage, and if the turns ratio is low, the output voltage will be lower than the input voltage.

4. How does the resistance of a transformer affect its efficiency?

The resistance of a transformer is an important factor in determining its efficiency. According to Ohm's Law, when the resistance of a circuit increases, the current decreases. In transformers, this means that a higher resistance will result in a lower output current. This results in more power being dissipated as heat, leading to lower efficiency. Therefore, transformers are designed with low resistance to minimize energy loss.

5. How does Ohm's Law explain the concept of power in transformers?

Ohm's Law also applies to power, which is the rate at which energy is transformed in a circuit. In transformers, the power is equal to the product of the voltage and current in both the primary and secondary coils. This means that the power in the primary coil is equal to the power in the secondary coil, neglecting losses. Ohm's Law helps to explain how the voltage, current, and power are related in a transformer.

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