How Transformers Work

The video tutorial explains how magnetic fields are generated around wires and how reversing the current direction affects these fields. It discusses the function of AC generators and transformers, highlighting the importance of alternating current for inducing voltage. The tutorial also covers the efficiency of transformers, the role of ferromagnetic cores, and the energy losses due to eddy currents and resistance. The video concludes by summarizing the key points discussed.

What happens to the magnetic field when the direction of the current is reversed?

• The magnetic field reverses direction.

• The magnetic field remains unchanged.

• The magnetic field disappears.

• The magnetic field strengthens.

Why do we observe a sine wave pattern in alternating current?

• Because the current flows in one direction.

• Because the voltage varies between maximum and minimum values.

• Because the voltage remains constant.

• Because the magnetic field is static.

What is the role of a second coil in a transformer?

• To increase the frequency of the current.

• To decrease the resistance of the circuit.

• To induce a voltage by the magnetic field.

• To stabilize the magnetic field.

Why is direct current not effective in transformers?

• Because it creates a constant magnetic field.

• Because it increases the voltage too much.

• Because it causes the coils to overheat.

• Because it reverses the magnetic field.

What is the purpose of using a ferromagnetic iron core in transformers?

• To reduce the frequency of the current.

• To concentrate the magnetic field and improve efficiency.

• To increase the resistance of the coils.

• To eliminate energy losses completely.