A uniform electric field and a uniform magnetic field exist in a region in the same direction. An electron is projected with velocity pointed in the same direction. The electron will

Explanation

C is correct. While an electric field alone wouldn't directly change the speed of a charged particle (electron), in this case, the presence of a uniform magnetic field in the same direction as the electric field creates a special condition.This specific configuration creates a Lorentz force that acts in the direction of the electron's motion. The Lorentz force is expressed as:F = q * (E + v x B)where:F is the force (N)q is the charge of the particle (C) in this case, the electron's charge (negative)E is the electric field (N/C)v is the velocity of the particle (m/s)B is the magnetic field (T)Since the electric and magnetic fields are in the same direction, and the velocity of the electron is also in the same direction, the cross product (v x B) becomes zero. Therefore, the first term (q * E) dominates the equation, resulting in a force in the direction of the electron's motion. This force, acting in the same direction as the electron's initial velocity, accelerates the electron, leading to an increase in its speed.