Answer:
The primary coil has 13,400 turns
Explanation:
Voltage Transformers
A transformer is an electrical apparatus that converts an alternating electrical voltage to another. Step-down transformers lower the voltage from higher levels (kilovolts) to consumer levels (120/240 Volts).
The ratio between both voltages can be computed as
[tex]\displaystyle r=\frac{V_1}{V_2}[/tex]
Where V1 is the primary voltage and V2 is the secondary voltage. This ratio depends on the turns ratio of the coils wounded in a common magnetic core.
[tex]\displaystyle r=\frac{N_1}{N_2}[/tex]
Being N1 the number of turns of the coils of the primary side and N2 the number of turns in the secondary coil. Both relations give us
[tex]\displaystyle \frac{N_1}{N_2}=\frac{V_1}{V_2}[/tex]
Solving for N1
[tex]\displaystyle N_1=\frac{V_1}{V_2}\cdot N_2[/tex]
We have:
[tex]V_1=12,000\ V\\V_2=120\ V\\N_2=134[/tex]
Calculate N1
[tex]\displaystyle N_1=\frac{12,000}{120}\cdot 134=13,400[/tex]
The primary coil has 13,400 turns
