Question

State Fleming’s left hand rule.

Answer 1

Hint: Fleming’s left hand rule was invented in the late 19^th century by John Ambrose Fleming. According to Fleming’s left hand rule, we use the thumb, index finger or the forefinger and the middle finger to represent directions of various parameters. It gives a relation between induced current, force and magnetic field in which the conductor is placed. This rule is used to determine the direction of the motion of a conductor which is moving inside the magnetic field.

Complete solution:
Fleming’s right hand rule is an interpretation which gives the direction of motion or force on a conductor when the conductor is moved in a magnetic field.

Fleming’s left hand rule states that if we stretch thumb, forefinger or the index finger and the middle finger in such a way that they are mutually perpendicular to each other then the thumb gives the direction of the motion of the conductor, index finger gives the direction of the magnetic field and the middle finger gives the direction of the induced current. Using Fleming’s left hand rule, it is possible to predict the direction of the force or motion of the conductor if the direction of current and magnetic field is known.

Note:
Students usually get confused with Fleming’s left-hand rule and Fleming’s right-hand rule. So, students should know the application of these two rules. Fleming’s left-hand rule is used for electric motors whereas Fleming’s right hand rule is used in electric generators. The purpose of left-hand rule is to determine the direction of the motion in an electric motor. The purpose of right-hand rule is to find the direction of the induced current when the conductor is moved in a magnetic field.