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A step-down transformer has 3000 turns on its primary coil and 20 turns on its secondary coil. The primary circuit is supplied with an effective AC voltage of 325 V.
a. What is the voltage in the secondary circuit?

b. If the current in the primary circuit is 1.25 A, what power is drawn by the primary circuit?

c. Assuming the transformer is perfectly efficient, what power is supplied to the secondary circuit?

Answer :

Hamzaahmedsgo

This question involves the concepts of turns ratio and power.

a. The voltage in the secondary circuit is "2.17 V".

b. The power drawn by the primary circuit is "2.71 watt".

c. Power supplied to the secondary circuit is "2.71 watt".

a. SECONDARY VOLTAGE

From the turns ratio formula we know that:

[tex]\frac{N_p}{N_s}=\frac{V_p}{V_s}\\\\V_s = \frac{N_sV_p}{N_p}[/tex]

where,

  • [tex]V_s[/tex] = voltage of secondary circuit = ?
  • [tex]N_s[/tex] = No. of turns in secondary cicrcuit = 20 turns
  • [tex]V_p[/tex] = voltage of primary circuit = 325 V
  • [tex]N_p[/tex] = No. of turns in primary circuit = 3000 turns

Therefore,

[tex]V_s=\frac{(20\ turns)(325\ V)}{3000\ turns}[/tex]

[tex]V_s = 2.17\ V[/tex]

b. POWER DRAWN BY PRIMARY CIRCUIT

Electrical power is given by the following formula:

[tex]P_p = I_pV_p[/tex]

where,

  • [tex]P_p[/tex] = power drawn by primary circuit = ?
  • [tex]I_p[/tex] = current in primary circuit = 1.25 A
  • [tex]V_p[/tex] = voltage of primary circuit = 325 V

Therefore,

[tex]P_p=(1.25\ A)(2.17\ V)\\\\P_p = 2.71\ watt[/tex]

c. POWER SUPPLIED TO SECONDARY CIRCUIT

Since the transformer is perfectly efficient. It means that the total power drawn by the primary circuit is supplied to the secondary circuit.

[tex]P_s=P_p\\\\P_s=2.71\ watt[/tex]

Learn more about turns ratio here:

https://brainly.com/question/25886292

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