Question

What are the similarities and differences between gravitational, electromagnetic and magnetic force?

Answer 1

Gravitational: -
Source: point mass -
Field intensity proportional to: M/r^2 -
Range: long range
Strength: weak -
Direction of field lines: toward center of mass
Electric Fields: -
Source: point charge -
Field intensity proportional to: Q/r^2 -
Range: short range -
Strength: strong
-Direction of field lines: toward center of charge
Magnetic Fields: -
Source: no point source, dipole required -Field intensity proportional to: n/a because no point source -Range: short range -Strength: strong -Direction of field lines: depends on the direction of the motion of a charge generating the magnetic field lines. otherwise they go from north to south.