question_answer

  A student performs an experiment to study the magnetic effect of current around a current carrying straight conductor with the help of a magnetic compass. He reports that (i) the degree of deflection of the magnetic compass increases when the compass is moved away from the conductor. (ii) the degree of deflection of the magnetic compass increases when the current through the conductor is increased. Which of the above observations of the student appears to be wrong and why?

Answer:

                  Rule: Fleming s right-hand rule. It states that if we stretch the thumb, forefinger and middle finger of our right hand such that they are mutually perpendicular to each other. If forefinger indicates direction of magnetic field and the thumb shows the direction of motion of conductor, then middle finger will show direction of induced current. Application: Electrical generator.