A straight current carrying conductor is placed in a magnetic field but no force acts on it. What can be the reason behind this?
The conductor is parallel to the magnetic field.
We know that when a current carrying conductor is placed in a magnetic field, a force is exerted on the conductor which can make the conductor move. The direction of the motion of the conductor represents the direction of the force acting on it. The direction of the force acting on the current carrying conductor is perpendicular to the direction of current as well as the magnetic field which we can find out by using Fleming's left-hand rule. But, no force acts on the conductor when it is kept parallel to the magnetic field.