Constant acceleration in uniform electric field

Steps:

• Positively charged particle experiences force F = qE towards negative plate.
• Uniform field E means constant force F.
• Acceleration a = F/m = qE/m is constant.
• Particle accelerates uniformly towards negative plate.

Why B is correct:

• Newton's second law (F = ma) states constant force produces constant acceleration.

Why the others are wrong:

• A: Constant speed requires zero net force, but force is constant and nonzero.
• C: Acceleration remains constant, not decreasing.
• D: Acceleration remains constant, not increasing.

Final answer: B