An electron moving with a uniform velocity along the positive $x$-direction enters a magnetic field directed along the positive $y$-direction. The force on the electron is directed along

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

Two ions have equal masses but one is singly ionized and second is doubly ionized. They are projected from the same place in a uniform transverse magnetic field with same velocity then:
$(a)$ Both ions will go along circles of equal radii
$(b)$ The radius of circle described by the single ionized charge is double of radius of circle described by doubly ionized charge
$(c)$ Both circle do not touches to each other
$(d)$ Both circle touches to each other

If the direction of the initial velocity of the charged particle is perpendicular to the magnetic field, then the orbit will be   or  The path executed by a charged particle whose motion is perpendicular to magnetic field is

A particle is moving in a uniform magnetic field, then

A charge of $1\,C$ is moving in a magnetic field of $0.5\,Tesla$ with a velocity of $10\,m/sec$ Perpendicular to the field. Force experienced is.....$N$