I just want the explaination to use Fleming's left hand rule in finding the direction of force in a given diagram. I would be grateful to know the explainations of the solved examples 1 and 2 from selina publications (the diagram based questions) as I am not getting what is given there.

Asked by aaryamehta46 | 24th Mar, 2017, 05:14: PM

Expert Answer:

In both the examples, a coil is shown placed between two poles of a magnet. So, one thing is sure that the direction of magnetic field is from N to S. So, for using Fleming's left hand rule place the index finger in that direction. The first part of the question asks to find the direction of current in the coil. This part is easy as we have to check the battery connection only. In both the questions, the current is from DCBA. For the second part of the question, force will be found by considering each arm, i.e. AB, BC, CD and DA, separately. Place your middle finger in the direction BA, CB, DC and AD, respectively. Then the direction of thumb will give you the direction of force. You will find that arm AB moves upwards and CD moves downwards. No effect on arm BC and AD. Hence, in this way you will be able to use Fleming's left hand rule effectively for all the questions.

Answered by Romal Bhansali | 24th Mar, 2017, 06:35: PM