Topic 6 Electricity Test - Physics

Ampere showed thgat magentic force was circular and produced a cylinder of magnetism around the wire and the magnetic field.

Normally, a compass needle points north due to the Earth’s magnetic field, so Oersted brought the compass near an electrical current, which caused the needle’s direction to change. This led him to discover that electrical current creates a magnetic field, and can impact a compass needle in 2 main ways: • The direction the needle moves depends on the direction of current flow in the wire. • The amount of movement in the needle depends on the strength of the current.

The interactions between electric currents and magnetic fields and how they are connected. -Electrical currents create magnetic fields - Oersted -Changing magnetic fields can create an electrical current. - Faraday

The process of movement between a magnet and a coiled wire to create an electrical current. This is called an electromagnetic generator. Current can increase with: -More loops of wire -A stronger magnet -The speed at which the magnet is moved

The byproduct of when energy is used, it is the unnecessary energy that follows the main type of energy used. For example, when using mechanical energy in a blender, sound energy is also used.

When electricity passes through a metal to temporarily turns it into a magnet. For example, a nail.

A generator uses a coil/armature rotating in a magnetic field (from a magnet or electromagnet) to produce an electric current through electromagnetic induction. Mechanical –> Electrical energy

A motor is a battery/electricity-powered device that uses a rotor and a stator to produce interacting magnetic fields. The interaction of these fields causes the rotor to spin, converting electrical energy into mechanical energy.

AC = Current alternates direction of flow DC = The current continues in one direction -Both can be used in a motor and genrator!

An AC generator uses the principles of electromagnetic induction to convert mechanical energy into electrical energy and produce an alternating current. This uses slip rings to connect the coil/armature to the main circuit.

The rotating coil in a generator, the turning motion is called TORQUE

The DC Generator works the same way as an AC generator, in the sense that both use an armature to cut through a magnetic field and induce current into a wire. But in the DC generator, the armature is connected to the main circuit by a split-ring commutator. The commutator selectively collects the current from the armature, which results in it flowing in one direction.

Slip-rings, found in an AC generator, connect the armature to the main circuit.

Motor = Electricity to Motion Generator = Motion to Electricity

A DC motor uses direct current to make the rotor (armature) an electromagnet. The rotor interacts with the stator’s magnetic field, which makes it rotate. A split-ring commutator reverses the armature every half turn so the rotor keeps spinning in the same direction, producing mechanical energy.

AC current flows through the rotor, turning it into an electromagnet. The magnetic fields of the rotor and stator interact (attraction and repulsion between north and south poles), which causes the rotor to spin and produce electricity

Rotor: Rotating core that becomes an electromagnet when current flows. Stator: Stationary magnets or electromagnets that create a magnetic field.