Problem #0155 Electricity & Magnetism Sub-menu Problem #0157 Chapters Chapters


Problem 34.7 (RHK)

An electron in a uniform magnetic field has a velocity . It experiences a force . If , we have to calculate the magnetic field.

Solution:             Click For PDF Version

The force on an electron, charge e, velocity , in magnetic field is given by the equation

Data of the problem are


As , we will write the magnetic field as

We thus have the vector equation

We will use the properties of the cross- product


and rewrite equation as


It may be noted that the -equation is consistent with the -equation, as it also gives

Therefore, the magnetic field is