When an electric field is applied across a nonconducting liquid containing large

Question

When an electric field is applied across a nonconducting liquid containing large
colloidal particles, it is found that they align as shown in Figure 5.4. Explain this
phenomenon and suggest one condition when the particles will not align (ignore
gravitational effects). At low particle densities one often observes individual particles
shuttling back and forth between the two electrode surfaces. Explain this effect in
more detail than is given in Figure 5.4.

O O O O O O O O O Externally applied field No field Random particles Particles align FIGURE 5.4 lf the particles are conductors in a nonconducting medium, they can pick up electrons from the bottom surface and then be shuttled to the top, where they unload their "cargo and then pick up a proton and return to discharge it at the bottom surface. The processes are then repeated, giving rise to back-and-forth shuttling (and a current) so long as the electric field E is maintained across the gap.

Explanation / Answer

The polarization effect can be used to describe the situation since the medium is non-conducting.
Ions in the medium have some kind of charge with them (negative, positive or neutral). When electric field
is applied around the system then the ions/particles react according the interaction between them. The electric
field imparts some charge on the particles by polarizing them and hence all polarized particles align themselves
which in turn depend upon the force. If electric field is not applied then particles don't get polarized and hence
they do not align. So this will be the condition for the particles not to align.

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.