Test: Magnetic Force - Class 10 MCQ

An electric current flowing through a conductor produces a magnetic field, as stated by the interaction of moving charges. This phenomenon is fundamental to electromagnetism and finds applications in various technologies like electric motors and generators.

The magnetic field inside a long straight solenoid carrying current is the same at all points. This characteristic is a key property of the magnetic field produced by such a configuration.

• Fleming's left-hand rule is used to determine the direction of the force on a current-carrying conductor in a magnetic field.
• By aligning the thumb, forefinger, and middle finger of the left hand in specific directions, one can easily determine the resultant force acting on the conductor.
• This rule is a fundamental concept in understanding the interaction between magnetic fields and current-carrying conductors.

A current-carrying rod experiences a force perpendicular to its length and the magnetic field, as described by the interaction between current and magnetic fields in electromagnetism.

• The assertion that the force on a current-carrying conductor in a magnetic field depends on the directions of both the current and the magnetic field is correct. This relationship is described by the right-hand rule for the force on a current-carrying conductor in a magnetic field.
• The reason that the force is maximum when the current is perpendicular to the magnetic field is also correct. This is a fundamental principle of electromagnetism.
• However, the reason does not directly explain why the assertion is true. While it is true that the force is maximum when the current is perpendicular to the magnetic field, this fact alone does not fully explain the dependence of the force on the directions of both the current and the magnetic field. Hence, Option B is the correct answer.

When a current-carrying conductor is oriented parallel to the magnetic field lines, the force experienced by the conductor is zero. This is because the force on the conductor is given by F=BILsin⁡θ, where θ is the angle between the direction of the current and the magnetic field. When θ is 0 degrees (parallel), sin⁡θ is zero, resulting in no force.