Assertion (A) : A current carrying straight conductor experiences a force when placed perpendicular to the direction of magnetic field.

Reason (R) : The net charge on a current carrying conductor is always zero.

• Assertion (A) is True: A current-carrying straight conductor experiences a magnetic force when placed in an external magnetic field, and this force is maximum when the conductor is perpendicular to the field lines (as demonstrated in Activity 12.7).
• Reason (R) is True: A current-carrying conductor is always electrically neutral as a whole. The number of negatively charged conduction electrons moving through the metallic lattice is exactly equal to the number of positive metal ions in the lattice. Thus, the net charge on the conductor is zero.

Explanation Link: The magnetic force on the current-carrying conductor is due to the magnetic Lorentz force acting on the individual moving charges (free electrons) inside the conductor ($F = I L B \sin\theta$). The fact that the net charge of the conductor is zero does not explain why it experiences a force; indeed, if the charges were stationary, there would be no magnetic force despite the net charge being zero. The force arises purely due to the motion* of the charge carriers (current). Therefore, while both statements are individually true, the Reason is not the correct explanation of the Assertion.