The correct option is Both A and R are true but R is NOT the correct explanation of A
Explanation
The interaction between a magnetic field and a current-carrying conductor results in a mechanical force. The direction of this force is determined by vector relationships (often visualized using Fleming's Left-Hand Rule), while the magnitude is determined by the physical parameters of the system, described by the equation \( F = B I L \sin\theta \).
Statement-wise Analysis
- Assertion (A): Correct. The direction of the force on a current-carrying conductor is perpendicular to both the direction of the current and the magnetic field. According to Fleming's Left-Hand Rule, reversing the direction of the current (while keeping the magnetic field constant) reverses the direction of the resultant force.
- Reason (R): Correct. The magnitude of the force (\( F \)) is directly proportional to the magnetic field strength (\( B \)), the current (\( I \)), and the length of the conductor (\( L \)). Therefore, the strength of the magnetic field directly influences the magnitude of the force.
Conclusion: While both statements are scientifically accurate, the Reason (R) explains the magnitude of the force, whereas the Assertion (A) pertains to the direction. The dependence on field strength does not explain the directional reversal caused by reversing the current. Thus, R is not the correct explanation for A.
Key Takeaway
The direction of the magnetic force is governed by the relative orientation of the current and magnetic field vectors, whereas the magnitude is governed by the strength of the field, current, and conductor length.