Given below are two statements:
Statement I: The electric force changes the speed of the charged particle and hence changes its kinetic energy; whereas the magnetic force does not change the kinetic energy of the charged particle.
Statement II: The electric force accelerates the positively charged particle perpendicular to the direction of electric field. The magnetic force accelerates the moving charged particle along the direction of magnetic field.
In the light of the above statements, choose the most appropriate answer from the options below:

We need to evaluate two statements about electric and magnetic forces.

Statement I: "The electric force changes the speed of the charged particle and hence changes its kinetic energy; whereas the magnetic force does not change the kinetic energy of the charged particle."

This is CORRECT. The electric force $$\vec{F} = q\vec{E}$$ can do work on a charged particle, thereby changing its speed and kinetic energy. The magnetic force $$\vec{F} = q\vec{v} \times \vec{B}$$ is always perpendicular to the velocity, so it does zero work. Hence, the magnetic force cannot change the speed or kinetic energy of a charged particle.

Statement II: "The electric force accelerates the positively charged particle perpendicular to the direction of electric field. The magnetic force accelerates the moving charged particle along the direction of magnetic field."

This is INCORRECT. Both parts are wrong:

- The electric force acts along the direction of the electric field (for positive charges), not perpendicular to it: $$\vec{F} = q\vec{E}$$.

- The magnetic force $$\vec{F} = q\vec{v} \times \vec{B}$$ is perpendicular to both $$\vec{v}$$ and $$\vec{B}$$, not along the direction of $$\vec{B}$$.

Therefore, Statement I is correct and Statement II is incorrect.

Hence, the correct answer is Option C: Statement I is correct but Statement II is incorrect.