Does an induced dipole-induced dipole need an outside influence to make it induced?

[Nicole L 2F]

During one of Dr. Lavelle's lectures, he mentioned that N2 was nonpolar but became an induced dipole due to another dipole (HCl). Then, he had an example of two N2 molecules for induced dipole-induced dipole interaction. I wondered if we needed another dipole, or any outside influences, near one of the N2 molecules to make N2-N2 an induced dipole to induced dipole interaction. Or if two N2 molecules interact together, it automatically counts as induced dipole-induced dipole interaction. Hope this makes sense :,)

[leafypsycho]

Hi Nicole!
Yes, it totally makes sense! When two N2 molecules come near each other, there is no need for an outside influence to make this an induced dipole-induced dipole interaction. It is automatic as you said. Although N2 molecules are polar, therefore, having no permanent dipole, the electrons of one of the N2 molecules can temporarily shift to one side creating a temporary dipole due to its constantly fluctuating electrons. This slight dipole then induces a dipole in the other N2 molecule, allowing the induced dipole-induced dipole interaction (LDF).
Hope this helped!