Complete Question
Two spherical shells have a common center. A -1.6 x 10-6 C charge is spread uniformly over the inner shell, which has a radius of 0.030 m. A +5.1 x 10-6 C charge is spread uniformly over the outer shell, which has a radius of 0.15 m.What are the magnitude and direction of the electric field at a distance 43.5 mm from the center of the shells.
Answer:
The magnitude is [tex]E = 7.6021*10^{6} \N/C[/tex]
The direction is radially inward toward the center
Explanation:
From the question we are told that
The charge on the inner shell is [tex]q_i = -1.6*10^{-6} \ C[/tex]
The radius of the inner shell is [tex]c_1 = 0.030 \ m[/tex]
The charge on the outer shell is [tex]q_o = 5.1*10^{-6}\ C[/tex]
The radius of the outer shell is [tex]c_2 = 0.15\ m[/tex]
The distance considered is [tex]r = 43.5 \ mm = 0.0435 \ m[/tex]
Generally the electric field at the position considered is mathematically represented as
[tex]E = \frac{Q_c }{4\pi r^2 \epsilon_o }[/tex]
Here [tex]Q_c[/tex] is the charge which is enclosed by the distance considered which in this case is the charge on the inner shell
So [tex]Q_c =q_i = -1.6*10^{-6} \ C[/tex]
Hence
[tex]E = \frac{-1.6 *10^{-6} }{4* 3.142 *0.0435^2* 8.85*10^{-12} }[/tex]
=> [tex]E = -7.6021*10^{6} \N/C[/tex]
The negative sign is show that the direction of the field is radially inward toward the center