Question

Fleming’s left hand rule is used to find:
A. The direction of magnetic field
B. The direction of current
C. The direction of magnetic force acting on a conductor
D. None of these

Answer 1

Hint
Current carrying conductors placed in a magnetic field are subjected to a force. This force has a direction which is given by Fleming’s left hand rule.

Complete step by step answer
Fleming's left hand rule is an accurate and simple way to find the direction of force exerted on a conductor placed in an electric motor when the magnetic field direction and the current direction are known. John Ambrose Fleming, an English electrical engineer gave this simple rule in the late 19th century.
Although originally used for finding the direction of the force, this rule can be used to find the direction of any of the three quantities, if two of them are known. As the name suggests, the fingers and thumb of the left hand are used as props. The thumb represents the direction of the force exerted on the conductor while the fore finger denotes the direction of the magnetic field. The middle finger represents the direction of the flow of current.
Hence, the correct answer is option C.

Note
Fleming’s left-hand rule is generally used electric motors and primarily serves as a visual mnemonic. On the other hand, Fleming’s right hand rule is also used to find the direction of the magnetic force on a moving charge, but it is used for electric generators. Since the direction of force and the direction of the magnetic field is the same in both the cases, the direction of current in the conductor is reversed for a motor and a generator.