A straight conductor of length 0.5 m carries 2 A at right angles to a 0.4 T magnetic field. The force on it is:

1. The force on a current-carrying conductor in a magnetic field is F = B·I·L·sin θ. 2. The angle between current and field is 90°, so sin θ = 1. 3. Substitute the given values: F = 0.4 × 2 × 0.5 × 1. 4. F = 0.4 N. 5. Option A is off by a factor of ten; C and D overshoot by powers of ten. 6. So the correct force is 0.4 N. _Source: syllabus Science Ch 13 'Magnetic Effects of Electric Current' (learncbse.in extract)_