Answer:
The number of turns in the secondary coil is 28.
Step-by-step explanation:
Given that,
Input voltage given to the transformer,
![V_p=111\ V](https://img.qammunity.org/2021/formulas/physics/college/ue1wtamkgwbl2yfeuhmgk56ht43zck3ihq.png)
Output voltage supplied to the video game,
![V_s=9\ V](https://img.qammunity.org/2021/formulas/physics/college/j77zxvgvab4mvcwr9d6pp9pjhazm0rr5xu.png)
Number of turns in the primary coil,
![N_p=340](https://img.qammunity.org/2021/formulas/physics/college/r6oq9xtts7slsggbliktdkyoqatg7q5cwf.png)
We need to find the number of turns in its secondary coil. We know that the transformer equation is given by :
![(V_s)/(V_p)=(N_s)/(N_p)\\\\N_s=(V_s)/(V_p)* N_p\\\\N_s=(9)/(111)* 340\\\\N_s=27.56](https://img.qammunity.org/2021/formulas/physics/college/h3pw7bylm8yetu40vqfg6dzfcvklrw57gf.png)
or
![N_s=28](https://img.qammunity.org/2021/formulas/physics/college/r1xh34t86cmcyf9yhuywr3me6qbj1g0u9w.png)
So, the number of turns in the secondary coil is 28.