COMEDK2023Evening ShiftPhysicsMagnetic Effects of CurrentActual
A magnetic field does not interact with:
Options
- AA current carrying straight conductor
- BAn electric charge at rest.
- CA moving electric charge
- DA moving permanent magnet
Correct answer
B. An electric charge at rest.
Step-by-step solution
The magnetic force F on a charge q moving with velocity v in a magnetic field B is given by the Lorentz force law: F = q( v B ) . If the electric charge is at rest, its velocity v = 0 . Substituting v = 0 into the force equation, we get F = q(0 B ) = 0 . Therefore, a magnetic field exerts no force on an electric charge at rest. Answer: An electric charge at rest.