physics-Electric & magnetic fields
posted by Sandhya on .
A proton traveling at 10^4 m/s in the positive x-direction, enters a region where there is uniform electric field of magnitude 10 v/m and a uniform magnetic field of magnitude 10^-2 T. The electric and magnetic fields are parallel and are in the z-direction. In the following statements which of the two are false
A. When the proton enters the fields, the magnitude of magnetic force on it is ten times the magnitude of electric force
B. The initial acceleration of the proton is in the y-z plane, at 84 degrees to the z-axis and at 6 degrees to the negative y axis
C. When the proton enters the fields the magnetic force on it is perpendicular to the electric field
D. The electric force on the proton is constant
E. The magnetic force on the proton is constant
F. The speed of the proton changes with time
G. The path of the proton is a uniform helix
Obviously, C, D, is true, E is true if one ignores direction of force, F is true (as the E field accelerates the proton), and since perpendicular speed is constant, G is true. Gee, it turned out easy.
think out G.