The SI units of magnetic field are tesla (T). In Equation 19-1, if charge \(q\) is in coulombs (C), speed \(v\) is in meters per second (m/s), and magnetic field magnitude \(B\) is in tesla (T), the force \(F\) is in newtons (N). So \(1\ \mathrm{T}\) is the same as \(1\ \mathrm{N}\ \cdot \mathrm{s} / (\mathrm{C} \cdot \mathrm{m}\)) or \(1\ \mathrm{N} /(\mathrm{A} \cdot \mathrm{m}\)). (Recall that one ampere equals one coulomb per second: \(1\ \mathrm{A} = 1\ \mathrm{C}/\mathrm{s}\).)