Question

СРОЧНО,ПОМОГИТЕ РЕШИТЬ,!!!!!!!!!!!Понижающий трансформатор с коэффициентом трансформации k = 4,0 включен в сеть с напряжением U1 = 220 В. Определите КПД η трансформатора, если потерь энергии в первичной обмотке не происходит, а напряжение на вторичной обмотке U2 = 50 В.

Answer 1

Найдем сначала номинальное значение выходного напряжения $U_{2n}= \frac{U_{1}}{k} = \frac{220B}{4,0} =55B$

Ну теперь можно найти КПД $n= \frac{U_{2}}{U_{2n}} *100= \frac{50B}{55B} *100=91$

Answer 2

Calculation of Transformer Efficiency (КПД трансформатора)

To determine the efficiency (КПД) of the transformer, we need to use the formula:

η = (Pout / Pin) x 100%

Where: - η is the efficiency of the transformer, - Pout is the output power (power on the secondary side), - Pin is the input power (power on the primary side).

In this case, we are given the following information: - The transformer has a transformation ratio (коэффициент трансформации) of k = 4.0. - The input voltage (напряжение на первичной обмотке) is U1 = 220 V. - The output voltage (напряжение на вторичной обмотке) is U2 = 50 V.

To calculate the efficiency, we need to determine the output power (Pout) and the input power (Pin).

Calculation of Output Power (Pout)

The output power (Pout) can be calculated using the formula:

Pout = (U2^2) / R2

Where: - U2 is the output voltage, - R2 is the load resistance on the secondary side.

However, in this case, we are given that there are no energy losses in the primary winding (потерь энергии в первичной обмотке). Therefore, we can assume that the load resistance on the secondary side is zero (R2 = 0).

Thus, the output power (Pout) can be considered as zero.

Calculation of Input Power (Pin)

The input power (Pin) can be calculated using the formula:

Pin = (U1^2) / R1

Where: - U1 is the input voltage, - R1 is the load resistance on the primary side.

Since we are not given any information about the load resistance on the primary side, we cannot calculate the input power (Pin) accurately. Without this information, it is not possible to determine the efficiency (КПД) of the transformer.

Therefore, without the value of the load resistance on the primary side (R1), we cannot calculate the efficiency (КПД) of the transformer.

If you have any additional information or if there is anything else I can assist you with, please let me know!