PY 212 Study Guide - Midterm Guide: Electric Dipole Moment, Dielectric
Document Summary
Uniformly charged sphere: the e-field inside is zero, the e-field outside is the same as a point charge, electric potential is the same everywhere inside, the electric potential outside is the same as a point charge. Chapter 19 summary: v is a scalar, v and q have the same sign, v obeys superposition. Only valid for a uniform e-field. (cid:1848)(cid:3043)(cid:3042)(cid:3041) (cid:3045)=(cid:1869)(cid:1870) Electric potential: obeys superposition, equipotential lines cross e-field li(cid:374)es at 90 , the e-field goes from high-v to low-v, ele(cid:272)t(cid:396)i(cid:272) pote(cid:374)tial does(cid:374)(cid:859)t (cid:272)ha(cid:374)ge alo(cid:374)g a path pe(cid:396)pe(cid:374)di(cid:272)ula(cid:396) to the e-field (i. e. along an equipotential line). Work: for conservative forces (like the electric force): (cid:1849)= (cid:1842)(cid:1831, for nonconservative forces: (cid:1831)+ (cid:1842)(cid:1831)=(cid:1849)(cid:3041, for constant forces: w=(cid:1832) =(cid:1832)(cid:1856)(cid:1855)(cid:1867)(cid:1871)(cid:4666)(cid:4667, two methods to double check the sign of the work: If the di(cid:396)e(cid:272)tio(cid:374) of a fo(cid:396)(cid:272)e is the sa(cid:373)e as the di(cid:396)e(cid:272)tio(cid:374) of a(cid:374) o(cid:271)je(cid:272)t(cid:859)s displa(cid:272)e(cid:373)e(cid:374)t, then the force does positive work.
