# Search results

1. ### I dont understand where i went wrongplease help

a velocity selector consists of magnetic and electric fields. if B= 0.015 find the value of E such that a 750 eV electron is moving along the + x- axis and is undeflected. this is what i did.. the magnetic force=electric force so qvB=qE or vB=E K= .5 mv^2 and r= mv/qB so k...
2. ### Direction of magnetic force

how do you find the direction of the magnetic force on a current loop..a loop that experiences a torque? i know you use some kind of right hand rule but im confused also..the direction of a charged particle in a magnetic field please helpppppp
3. ### The current balance- an application

does anyone know what the current balance can be used for..ie. a practical application of the current balance?
4. ### Electric potential at a point in a sphere

im having trouble finding the electric potential at a point inside a sphere at r= 40 cm where the radius of the sphere is 50 cm and the charge Q is 12 micro C. i know that v= kQ/r at a point on the surface and at a point outside the sphere but what to i do now that i cant use total charge...
5. ### Electric potential in a uniform electric field please help

k im really confused about how to go about setting up the intergral of Eds. how do u choose the limits of integration and how do u know whether to write Va-Vb= -(integral) E ds or Vb-Va = - (integral) E ds its really frustrating me i thought i understood but i realised i really dont my...