Direction of electric field? See picture

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1 Answer
Jun 22, 2017

A

Explanation:

Electric field is electric force per unit charge. And the direction of the field is the direction of the electric force it would exert on a positive test charge.

If a positive test charge is placed at point #P#.
Force due to #+Q# charge on the test charge would be repulsive. Therefore, direction of force at #P# would be away from #+Q#
#vecE_([+Q]->P)#

Similarly, force due to #-Q# charge on the test charge would be attractive. Therefore, direction of force at #P# would be towards #-Q#
#vecE_(P->[-Q])#

Draw two vectors at point #P# of equal magnitude and directions as discussed above. The resultant of these two vectors will point in a direction as shown in the figure below.
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