A cell membrane consists of an inner and outer wall separated by a distance of approximately 10nm. Assume that the walls act like a parallel plate capacitor, each with a charge density of 10^(−5) C/m^2, and the outer wall is positively charged. Although unrealistic, assume that the space between cell walls is filled with air.
(A) What is the magnitude of the electric field between the membranes?

a) 1×10^6 N/C
b) 1×10^15 N/C
c) 5×10^5 N/C
d) 9×10^2 N/C

(B) What is the magnitude of the force on a K+ ion between the cell walls?

a) 2×10^13 N
b) 9×10^13 N
c) 2×10^11 N
d) 3×10^12 N

(C) What is the potential difference between the cell walls?

a) 6×10^3 V
b) 1×10^7 V
c) 10 V
d) 1×10^2 V

(D) What is the direction of the electric field between the walls?

a) There is no electric field.
b) Toward the inner wall.
c) Parallel to the walls.
d) Toward the outer wall.

1) A

2) A

3) D

Explanation:

For parallel plates,the electric field E is given by:

E = σ / ε(o), where

E = Electric Field

σ = surface charge density

E = 10^-5 / 8.85*10^-12

E= 1.13*10^6 which is approximately 1*10^6 N/C, option A

B) K has a charge of 1.6*10^-19

F= q*E= (1.13*10^6) * (1.6*10^-19)

F= 1.8*10^-13 Which is approximately 2*10^-13 N, option A

C) Potential difference ,V = Ed

d = 10 nm= 1*10^-9

V = 1.13*10^6 * 1**10^-9

V = 0.0113 v

V = 1.13×10^-2 which is approximately 1x10^-2v, option D

the entire statement is true and correct.  

there's no diagram, nothing is illustrated, and no question is asked.

the order for strong to weak forces such as

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force

the fundamental forces are those forces that act between to objects or element to make interactions. there are four types of fundamental forces such as strong and weak nuclear forces (due to protons and electrons), electromagnetic force (due to the motion of electrons) and gravitational force (due to orbital movement of the planet). if these forces are arranged on the basis of their maximum strength then the order is

strong nuclear force → electromegnetic force → weak nuclear force → gravitational force