A potential difference of $$600$$ V is applied across the plates of a parallel plate capacitor. The separation between the plates is $$3$$ mm. An electron projected vertically, parallel to the plates, with a velocity of $$2$$×$$106ms$$−$$1$$ moves undeflected between the plates. What is the magnitude of the magnetic field between the capacitor plates?

Question

A potential difference of $$600$$ V is applied across the plates of a parallel plate capacitor. The separation between the plates is $$3$$ mm. An electron projected vertically, parallel to the plates, with a velocity of $$2$$×$$106ms$$−$$1$$ moves undeflected between the plates. What is the magnitude of the magnetic field between the capacitor plates?

Infinity Learn · Accepted Answer

Electric field $$E=Vdwhere$$ V is the potential difference between the plates and d, the separation between them.$$d=3mm=3$$×$$10$$−$$3mE=Vd=6003$$×$$10$$−$$3=2$$×$$105Vm$$−$$1Since$$ the electron moves undeflected between the plates, the force due to magnetic field must balance the force due to electric field. $$ThusBev=eEB=Ev=2$$×$$1052$$×$$106=0.1T$$

Motion of a charged particle

Remember concepts with our Masterclasses.

Ready to Test Your Skills?

free study material