Question

A transformer draws 19 W of power from a 220 V power line, stepping the voltage down to 8.0V. What is the equivalent resistance of the input circuit?

Answer 1

The equivalent resistance of the input circuit is approximately 2547.37 ohms.

Step-by-step explanation:

Calculate the current in the transformer:

Current = Power / Voltage

Current = 19 W / 220 V ≈ 0.0864 A

Calculate the equivalent resistance using Ohm's Law:

Equivalent Resistance = Voltage / Current

Equivalent Resistance = 220 V / 0.0864 A ≈ 2547.37 ohms

Therefore, the transformer's input circuit has an equivalent resistance of approximately 2547.37 ohms. This represents the combined resistance of all components within the input circuit, including the transformer itself and any connected wires or devices.

Note: This calculation assumes ideal transformer operation, neglecting factors like transformer efficiency and internal losses.

Answer 2

The equivalent resistance of the input circuit is 2547.36 Ω.

Step-by-step explanation:

Given : A transformer draws 19 W of power from a 220 V power line, stepping the voltage down to 8.0V.

To find : What is the equivalent resistance of the input circuit?

Solution :

The relationship between power, voltage, and resistance is given by,

`P =(V^2)/(R)`

The voltage is V=220 volt

The power is P=19 W

Substitute the value,

`19=((220)^2)/(R)`

`19=(48400)/(R)`

`R=(48400)/(19)`

`R=2547.36`

The equivalent resistance of the input circuit is 2547.36 Ω.