Video Transcript
Which of the following is the
correct unit for the strength of a magnetic field? (A) Watt, (B) joule, (C) coulomb,
(D) tesla, (E) newton.
The question asks us what the
correct unit for the strength of a magnetic field is. A magnetic field magnitude can be
related to some familiar quantities by the equation force equals magnetic field
magnitude multiplied by current multiplied by length of wire. We can immediately see that
magnetic field magnitude cannot be equal to force, as this is the subject of the
formula that has magnetic field magnitude as one of its terms. We can then eliminate the unit
newton as this is the unit of force.
Let us consider the remaining
options. One option is watt. This is the unit of power, so it
cannot be the unit for the strength of a magnetic field. Another option is joule. This is the unit of energy, so it
cannot be the unit for the strength of a magnetic field. Another option is coulomb. This is the unit of electric
charge, so it cannot be the unit for the strength of a magnetic field. The only remaining option is
tesla. This is actually the correct unit
for the strength of a magnetic field.
