Point charges q_1 = +5.00 muC and q_2 = 5.00 muC are placed at adjacent comers o
ID: 1512521 • Letter: P
Question
Point charges q_1 = +5.00 muC and q_2 = 5.00 muC are placed at adjacent comers of a square for which the length of each side is 5.00 cm. Point a is at the center of the square. What is the electric field (magnitude and direction) at point a due to the two charges? What is the electric potential at point a due to the two charges? (Take the electric potential to be zero at a distance infinitely far from both charges) A point charge q_3 = -8.00 muC is placed at point a, what is the electric force (magnitude and direction) exerted on charge q3 by the two charges q_3 and q_2? How much work does it take to move charge from point a to a point that is infinitely far from both charges?Explanation / Answer
Here
q1 = q2 = 5 * 10^-6 c
r = 0.05/sqrt(2)
r = 0.035 m
a)
the x-components of electric field due to the two charges at
point a cancel only y-component remains
so
net electric field is E = 2 * k * q / r^2 * sin (theta)
E = 2 * 9 * 10^9 * 5 * 10^-6 / sqr(0.035) * 1/sqrt(2)
E = 51.95 * 10^6 N/c---------------------downward direction
b)
electric potential is
V = 2 * k * q/ r
V = 2.57 * 10^6 V
c)
F = q3 * E
F = 8 * 10^-6 * 51.95 * 10^6
F = 415.6 N--------------------------upward
d)
work W = q3 * V
W = 8 * 10^-6 * 2.57 * 10^6
W = 20.56 J