AN ALPHA PARTICLE MOVING TOWARDS NORTH IS DEFLECTED TOWARDS WEST. CAN YOU PLS EXPLAIN ME HOW CAN WE USE FLEMING'S LEFT HAND RULE TO FIND THE DIRECTION OF EXTERNAL DEFLECTING MAGNETIC FEILD? PLS EXPLAIN STEPWISE

Asked by archita123 | 25th May, 2015, 05:08: PM

Expert Answer:

According to Fleming's left hand rule, if the index finger points in the direction of magnetic field and the middle finger points in the direction of current then the thumb gives the direction of force on the conductor.
 
Now, for alpha particle, it is moving towards North. It is a positively charged particle. So, according to convention the direction of current will be towards south. Hence, the middle finger will point southwards.
 
The alpha particle is deflected towards west. So, the thumb is pointing westwards.
 
Therefore, keeping our fingers of left hand in above mentioned positions, we can see that the finger points upwards. Hence, the direction of magnetic field is upwards.
 

Answered by Romal Bhansali | 26th May, 2015, 06:41: PM