Electrical and Magnetic Devices: Key Concepts and Applications

Electrical Devices: Key Concepts

Device that converts electrical energy into mechanical energy?
Answer: Motor
When in a motor, the armature coils are connected in series, what can be said about the engine?
Answer: It must be in series
When a coil rotating in a magnetic field induces an alternating electromotive force (EMF), what does it cause?
Answer: Alternating Current (AC)
Device that increases or decreases the EMF depending on the arrangement of the coils?
Answer: Transformer
Device that converts mechanical energy into electricity?
Answer: Generator
How can an AC generator be converted to a DC generator?
Answer: By using split-ring commutators
The transformer only works with?
Answer: AC
Device to detect electric currents?
Answer: Galvanometer
Device using the magnetic fields produced by a winding and their respective magnets to produce a continuous rotational motion?
Answer: Motor

What is the rule for determining the direction of the magnetic field?
Answer: Right-hand thumb rule
What is the difference between a coil and a solenoid?
Answer: A coil is a wire wound in a spiral, and a solenoid is a coil wound around a metallic core.
What does a coil with electric current produce if a metal is placed between its turns?
Answer: It produces the effect of a magnet (with both North and South poles) and is called an electromagnet.
What is hysteresis?
Answer: It is the delay of magnetization concerning the magnetic intensity.
Explain what an electromagnet is.
Answer: It is a device consisting of a core and a coil through which electric current is circulated. It acts as a magnet with North and South polarities.
Mention at least two applications of electromagnets.
Answer: Doorbells, starters, alternators, and others.
What are the parts of an electric motor?
Answer: Rotor or armature (rotating coil), stator (outer coil), brushes, and others.
What is the difference between an AC generator and a DC generator?
Answer: The difference lies in the commutator rings located on the armature. A DC generator has a continuous ring, while an AC generator has a ring divided into two sections.
Mention the parts of a transformer and describe its function.
Answer: A transformer serves to increase or decrease AC voltage and is composed of primary and secondary coils and a metal core.

Which scientist discovered the relationship between electricity and magnetism?
Answer: Hans Christian Oersted
What was Ampere’s discovery?
Answer: He discovered a method to determine the direction of the magnetic field around a straight conductor.
Explain the right-hand thumb rule.
Answer: The thumb indicates the direction of the electric current, and the fingers indicate the direction of the magnetic field lines.
What is a solenoid?
Answer: It is a wire wound in a straight, tubular coil.
What is an electromagnet?
Answer: It is a combination of components: an iron core and a solenoid through which current flows.
The magnetism of materials is the result of what?
Answer: The movement of electrons within its atoms.
Which metals are more strongly magnetic?
Answer: Nickel, cobalt, and iron.
What is a ferromagnetic material?
Answer: A type of metal that has characteristics of magnetic order.
What do magnetic forces depend on?
Answer: They depend on the distance to the magnets.
What happens when you increase the electric field level?
Answer: Iron domains align with the magnetic field due to the current being produced.