Charged particle moving with a certain velocity along the +x-axis enters amagnetic field pointing toward the +z-axis. Because of an electric field along the +y­axis the charge particle continues to move along the +x-axis. What is the sign of thisparticle

Explanation:

A charged particle is deflected by magnetic field and its direction is given by right hand rule.

If the particle is Positively charged and magnetic field is in the positive +z axis then the particle will move clockwise w.r.t that axis. for the x-axis it is downward direction. While if the electric field is in positive Y direction then it will cause the positive charge to move in upward direction i.e. +Y axis.

The two forces will cancel out each other to move the charge particle in x axis.

Similar is the case with negatively charged particle i.e. magnetic field will cause the particle to move upward and Electric field cause the particle to move downward .

So charged particle can either be Positive or negative

the answer is the first electromagnet (a). this is because it has more coils around the ferromagnetic material. increasing the number of coils increases the surface area in which the metal interacts with the current in the coil. this enables more atoms in the metal to become aligned hence becoming more magnetized.