A particle that has a charge of 6.0 μC moves with a velocity of magnitude 5 × 105 m/s along the +x axis. It experiences no magnetic force, although there is a magnetic field present. The maximum possible magnetic force that the charge with the given speed could experience has a magnitude of 0.380 N. Find the magnitude and direction of the magnetic field. Note that there are two possible answers for the direction of the field.

and possible directions are +x axis and -x axis .  

Explanation:

Given :

Charge ,

Velocity , .

Maximum possible magnetic force ,

We know, Maximum force

Putting all values we get ,

Now , it is given that no force is applied in the charge .

Therefore, magnetic field must be parallel to it.

It can only happen in two ways , when field is along +x axis or -x axis .

Hence, this is the required solution.

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.