How can you get power used from step down transformers

In summary, there are two transformers between the house and the high-voltage transmission line, with the first one having a turns ratio of 1:29 and a primary current of 48 mA, while the second one has a turns ratio of 1:32 and delivers a 240-V emf to the house. Using the given values, the power being used by the house is calculated to be 1.1*10^4W.
  • #1
vaxopy
26
0
Suppose there are two transformers between your house and the high-voltage transmission line that distributes the power. In addition, assume that your house is the only one using electric power. At a substation the primary of a step-down transformer (turns ratio=1:29) receives the voltage from the high-voltage transmission line. Because of your usage, a current of 48 mA exists in the primary of this transformer. The secondary is connected to the primary of another step-down transformer (turns ratio=1:32) somewhere near your house, perhaps up on a telephone pole. The secondary of this transformer delivers a 240-V emf to your house. How much power is your house using? Remember that the current and voltage given in this problem are rms values.

Im lost :confused:
 
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  • #2
Hint: The voltage steps up as you move back towards the High voltage line, and power in equals power out.
 
  • #3
I don't know if this is right...
but here's what i did
Is = IpNp/Ns
=48*10^-3 * 29 = 1.392A
Is = IpNp/Ns
=1.392A* 32 = 44.544A
P(avg) = Irms*Vrms = 44.544A * 240V = 1.1*10^4W

is this right?
 

What is a step-down transformer?

A step-down transformer is an electrical device that is used to decrease the voltage of an alternating current (AC). It consists of two or more coils of wire that are wrapped around an iron core. The number of turns in each coil determines the voltage ratio of the transformer.

How does a step-down transformer work?

A step-down transformer works by using electromagnetic induction to transfer electrical energy from one circuit to another. The primary coil is connected to an AC power source, while the secondary coil is connected to the load. The changing magnetic field in the primary coil induces a current in the secondary coil, which results in a decrease in voltage.

What are the applications of step-down transformers?

Step-down transformers are commonly used in power distribution systems to reduce the high voltage of electricity generated at power plants to a lower voltage that is safe for use in homes and buildings. They are also used in electronic devices, such as chargers for laptops and cell phones, to convert high voltage AC to low voltage DC.

What are the advantages of using step-down transformers?

The main advantage of using step-down transformers is that they allow for the safe and efficient transmission of electricity over long distances. They also provide a way to convert voltage levels to meet the specific needs of different devices and appliances. Additionally, step-down transformers are relatively inexpensive and have a long lifespan.

Are there any risks associated with step-down transformers?

While step-down transformers are generally safe to use, there are some potential risks associated with them. These include electrical shock and fire hazards if the transformer is not properly maintained or if it is overloaded. It is important to follow safety precautions and regularly inspect and maintain transformers to prevent accidents.

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