question_answer

  The flow of current in a circular wire creates a magnetic field at its centre. How can existence of this field be detected? State the rule which helps to predict the direction of magnetic field.

Answer:

                  The existence of this field can be detected by using a magnetic compass needle. The direction of magnetic field is predicted by using Maxwell's right-hand thumb rule.                                                                                                       It states that, if you hold a current-carrying conductor in right-hand, such that, the thumb points in the direction of electric current, then the direction in which fingers encircle, gives the direction of magnetic field.