Question

A dipole consisting of two oppositely charged balls connected by a wooden stick is located as shown in the diagram at right. A block of plastic is located nearby,as shown. Locations B, C, and D all lie on a line perpendicular to the axis of the dipole, passing through the midpoint of the dipole.





Before selecting answers to the following questions, draw your own diagram of this situation, showing all the fields and charge distributionsrequested..
Answer the following questions by selecting either a direction (a-j) or an orientation of a polarized molecule (1-10) from the diagrams below.





1. Which of the arrows shown above best indicates the direction of the electric field at location C, due only to the dipole? (a-j)



2.Which of the arrows shown above best indicates the direction of the electric field at location D, due only to the dipole? (a-j)



3.Which of the diagrams shown above best indicates the polarization of a molecule of plastic at location C? (1-10)



4.Which of the diagrams shown above best indicates the polarization of a molecule of plastic at location D? (1-10)



5.Which of the following statements is correct? (a, b, c, or d)

a. A molecule located at D would be polarized more than a molecule located at C.

b. The polarization of a molecule located at D would be the same as the polarization of a molecule located atC.

c. A molecule located at C would be not be polarized at all.

d. A molecule located at D would be polarized less than a molecule located at C.



6.Which of the arrows shown best indicates the direction of the electric field at location B, due only to the dipole? (a-j)



7.Which of the arrows shown best indicates the direction of the electric field at location B, due only to the plastic block? (a-j)



The magnitude of the electric field at B due to the plastic is less than the magnitude of the electric field at B due to the dipole.


8.Which of the arrows shown best indicates the direction of the net electric field at location B? (a-j)





9.Which of the following statements is correct? (a, b, c, or d)

a. The electric field at B due only to the dipole would be smaller if the plastic block were not there.

b. The electric field at B due only to the dipole would be larger if the plastic block were not there.

c. The electric field at B due only to the dipole would be zero if the plastic block were not there.

d. The electric field at B due only to the dipole would be the same if the plastic block were not there.



10.Using the diagrammatic conventions discussed in the textbook and in class, a student drew the diagram below to help answer the questions asked above.Which of the following statements about the student's diagram are true? Check all that apply.
(a, b, c,)






a. The diagram shows mobile charges; this is wrong because an insulator does not have mobile charged particles.

b. The direction of polarization of the plastic block is wrong.

c. The diagram is correct; this is just a different way of drawing the polarization..

Answer 1

The red lines indicate the electric field due to a dipole and green lines indicate the equipotential lines.

At point C, E-field is in g direction.

At point D, E-field is in g direction.

At point C, molecules will be oriented as in 2 alignment, because it negative charge should align towards positive pole.

At point D, molecules will be oriented as in 2 alignment, because it negative charge should align towards positive pole.

At point B, E-field only due to dipole is in g direction.

At point B, E-field only due to plastic is in c direction.

At point B, total E-field is in g direction.

EDIT:

The electric field at B due to only dipole in absence of plastic will be same.

The diagram is incorrect, because only mobile charges can drift to rearrange themselves under the influence of E-field and plastic being an isulator, does not have mobile charges.