Question

A transformer has 25 turns in the primary coil and 200 turns in the secondary coil. If 24 V is connected to the primary coil and a 20-Ω device is connected to the secondary coil, calculate the current in Amperes passing through the device.

Answer 1

There is a relation between current, voltage and number of turns in a transformer

`Constant=(V_1)/(V_2)=(n_1)/(n_2)=(I_2)/(I1)`

We have the number of turns for both coils and the voltage on the primary. with this we can get the voltage on the second coil

`\begin{gathered} (24V)/(V_2)=(25)/(200) \\ \\ V_2=192V \end{gathered}`

With this voltage we can get the current by using the next formula:

`\begin{gathered} V=IR \\ \\ 192V=I\cdot20\Omega \\ I=9.6A \end{gathered}`

Answer: I=9.6A