A charge $Q$ moves parallel to a very long straight wire carrying a current $l$ as shown. The force on the charge is
Opposite to $O X$
Along $O X$
Opposite to $OY$
Along $OY$
An electron is moving in the north direction. It experiences a force in vertically upward direction. The magnetic field at the position of the electron is in the direction of
Write equation of Lorentz force.
Electrons moving with different speeds enter a uniform magnetic field in a direction perpendicular to the field., time periods of rotation will be :
A charged particle moves along circular path in a uniform magnetic field in a cyclotron. The kinetic energy of the charged particle increases to $4$ times its initial value. What will be the ratio of new radius to the original radius of circular path of the charged particle
If two streams of protons move parallel to each other in the same direction, then they