Four point charges are placed at the four corners of a square in two ways (a) and (b) as shown in figure. Will the (i) electric potential and (ii) electric field, at the centre of the square be the same or different in the two configurations and why?
Answers
okk ..
a= as in the figure u can see opposite charge on opposite sides .
let at the centre. there is a small positive charge. q
hence.
hence direction of force point A will be in the direction of point C
hence total force by A and point c will be 2f
similar to BD
force on centre by BD =2f
now
both the direction will be in 90 Degree to each other.
hence
Fnet on centre = 2√2F
b = similar charge on opposite sides then direction will be opposite hence total force =0
Given:
Four point charges are placed at the four corners of a square in two ways (a) and (b) as shown
To Find:
Will the (i) electric potential and (ii) electric field, at the center of the square be the same or different in the two configurations.
Solution:
In (a) , both positive charges are in the top and negative charges are on the bottom.
- Electric potential is a scalar quantity.
- Therefore net Electric potential = K/r ( q + q + -q + -q ) = 0
- Electric field due to positive charges will be directed downwards at the center.
- Electric field due to negative charges will be directed downwards at the center.
- Hence net electric field will be downwards.
In (b), positive charges and negative charges are kept at diagonal ends.
- Electric potential will be 0.
- Electric field due to two positive charges at center will cancel each other, since both are equally spaced from the center.
- Electric field due to two negative charges also cancel each other.
- Hence net electric field at the center = 0.
Hence the electric potential at the center of the square be the same or different and electric field, at the center of the square will be different.