Interactions between Electricity and Magnetism Interactions between electricity and magnetism all involve some motion of either charges (electricity) or changes in the magnetic field.

Mag/Elec Interactions Magnetic Force Magnetic Force There is a magnetic force whenever a charge (or charged object) moves across a magnetic field. There is a magnetic force whenever a charge (or charged object) moves across a magnetic field. The Force direction obeys the Right hand rule we discussed in class. The Force direction obeys the Right hand rule we discussed in class. The equation for this is F = q v B The equation for this is F = q v B q = amount of charge (C), v = velocity, B = magnetic field (Teslas) q = amount of charge (C), v = velocity, B = magnetic field (Teslas)

Magnetic Force on moving charge

Mag/Elec Interactions Right Hand Rule # 1 Right Hand Rule # 1 Point fingers in direction of moving charge q Point fingers in direction of moving charge q Orient your palm so its facing the direction of the magnetic field B Orient your palm so its facing the direction of the magnetic field B Extend your thumb, its the direction of the force. Extend your thumb, its the direction of the force. This force happens only when the charge moves perpendicular to the magnetic field B. This force happens only when the charge moves perpendicular to the magnetic field B.

Right hand rule for magnetic force

Mag/Elec Interactions A wire carrying a current creates its own magnetic field. A wire carrying a current creates its own magnetic field. This field is circular and its orientation is determined by Right hand rule #2 This field is circular and its orientation is determined by Right hand rule #2

Mag/Elec Interactions Right Hand Rule # 2: to determine the direction of the circular magnetic field around a wire carrying a current. Right Hand Rule # 2: to determine the direction of the circular magnetic field around a wire carrying a current. Direct your thumb along the wire in the direction of the current. Direct your thumb along the wire in the direction of the current. Your fingers curl in the direction of the circular magnetic field Your fingers curl in the direction of the circular magnetic field

Mag/Elec Interactions Electro-magnets Electro-magnets If you coil a wire into a helical form (like wrapping a wire around a cylinder) and run a current through it, each circular coil creates a small mag field. If you coil a wire into a helical form (like wrapping a wire around a cylinder) and run a current through it, each circular coil creates a small mag field. The mag field from each coil adds up to create what looks like a magnet with a North and South pole. The mag field from each coil adds up to create what looks like a magnet with a North and South pole. By running a current through this wire, you make a magnet. This is also known as a solenoid. By running a current through this wire, you make a magnet. This is also known as a solenoid.