Question

one kind of e-book display consists of millions of very small spheres that float in a thin fluid layer between two conducting transparent plates. each sphere is black on one side and white on the other, and possesses an electric dipole moment directed from the white side to the black. When an electric field is applied between the plates, the spheres rotate so that their dipole moment lines up with the field. Depending on the fields direction, either the black or the white sides of th espheres can be made visible. The dipole moment of the spheres can be modeled as two opposite charges of magnitude 3.5 x 10^-15 C, separated by a distancce of 100 micrometers (um). What is the maximum possible torque on a sphere if the electric field between the transparent plates is 4.0 x 10^5 N/C

Answer 1

Answer:

$1.4\times 10^{-13} Nm$

Explanation:

We are given that

Charge,q=$3.5\times 10^{-15} C$

Distance, d=$100\mu C=100\times 10^{-6} C$

$1\mu C=10^{-6}C$

Electric field,E=$4\times 10^5N/C$

We have to find the maximum possible torque on a sphere .

Electric dipole moment=qd

Using the formula

Electric dipole moment,p=$3.5\times 10^{-15}\times 100\times 10^{-6} Cm$

Maximum torque,$\tau=pE$

Using the formula

Torque,$\tau==3.5\times 10^{-15}\times 100\times 10^{-6}\times 4\times 10^5$

$\tau=1.4\times 10^{-13} Nm$

Hence, the maximum torque,$\tau=1.4\times 10^{-13} Nm$