Two electrons are located in a region of space where the magnetic field is zero. Electron A is at rest; and electron B is moving westward with a constant velocity. A non zero magnetic field directed eastward is then applied to the region. In what direction, if any will each electron be moving after the field is applied?

Electron A It remains stationary, while electron B continues moving westward

Explanation:

The force acting on each electron is given by F = Bevsinθ where B = magnetic field strength, v = velocity of electron, e = electron charge and θ = angle between B and v

Force electron A, v = 0, and θ = unknown, so F = Be × 0 × sinθ = 0.

So, no force acts on it and thus, it does not move. It remains stationary.

Force electron B, v = constant, acceleration, a = 0 and θ = 180, so F = Bevsin180 = 0.

So, no net force acts on it and thus, it does not change direction. It continues moving westward.

r=rho l/a where a is the area, l is the length and rho is resistivity so the greater the area the lesser the resistance thats why the earth pin is thicker bcos current follow the shortest path, so less resistive .

c)as speed changes, wavelength and frequency change.

everything changes!