Answer:
(a)
![V_s= (Ns*V_p)/(N_p)](https://img.qammunity.org/2020/formulas/physics/high-school/249eszbn0vn41p6jtms61liv6patb8n1b7.png)
(b)
![I=(V)/(R)](https://img.qammunity.org/2020/formulas/physics/high-school/59eau3i4v594xi0tdi2aoccytaiic5y1ac.png)
(c)
![P=VI](https://img.qammunity.org/2020/formulas/physics/high-school/isb13etf7eejgza2vz6inrmef6ksonpukc.png)
Step-by-step explanation:
The relationship between the voltage of the primary and secondary of a transformer depends on the number of turns the primary coil and the number of turns in the secondary coil. Mathematically is given by:
![(V_s)/(V_p) =(Ns)/(N_p)](https://img.qammunity.org/2020/formulas/physics/high-school/i5qrnvgm31ny01vgxu1y06lm4ynorj86r9.png)
Where:
![V_s=Voltage\hspace{3}in\hspace{3}secondary\hspace{3}coil](https://img.qammunity.org/2020/formulas/physics/high-school/uj3vdxit39wj60pt4efkr5yk02mn4bm5ks.png)
![V_p=Voltage\hspace{3}in\hspace{3}primary\hspace{3}coil](https://img.qammunity.org/2020/formulas/physics/high-school/cioaa1z4wq9yiert0lp5fiq0oi1ygb2d4q.png)
![N_s=Number\hspace{3}of\hspace{3}turns\hspace{3}on\hspace{3}secondary\hspace{3}coil](https://img.qammunity.org/2020/formulas/physics/high-school/93bn9bs9jjkl0g4w9mx1razc2hwq3bwidh.png)
![N_p=Number\hspace{3}of\hspace{3}turns\hspace{3}on\hspace{3}primary\hspace{3}coil](https://img.qammunity.org/2020/formulas/physics/high-school/5pqho8dedphocbmmp72s4t9tsl7vfwop7v.png)
Isolating Vs and replacing the data in the previous equation:
![V_s=(V_p*N_s)/(N_p)=(250*12)/(50)=60V](https://img.qammunity.org/2020/formulas/physics/high-school/jt4fxgnc14cmf2swh550hb0ggib20xjqxa.png)
(b) Using ohm's law:
![V=IR](https://img.qammunity.org/2020/formulas/chemistry/middle-school/54vvj0rpb2pdb10injvqqtxro0369imuvo.png)
Isolating I and replacing the data:
![I=(V)/(R) =(60)/(10) =6A](https://img.qammunity.org/2020/formulas/physics/high-school/hu2hbzfsqlpr62u74gux8vxgdpnytt7vc7.png)
(c) The Electric power is defined by:
![P=VI](https://img.qammunity.org/2020/formulas/physics/high-school/isb13etf7eejgza2vz6inrmef6ksonpukc.png)
Hence:
![P=(60)*(6)=360W](https://img.qammunity.org/2020/formulas/physics/high-school/bysqvrzequ33vr16337gy4wfypsg1nb1wj.png)