Question

Chapter 22, Problem 056 An electric dipole consists of charges 2e and 2e separated by 1.0 nm t is in an electric field of strength 4.5 10° N C Calculate e magnitude o e to que o e dipole when the dipole moment is a perallel to, b) perpendular , and c antiparallel to e ele i (a) Nurmber (b) Number (c) Number Units Units |

Answer 1

he dipole moment of electric dipole will be given as

P = 2 l q and hence torque on it in the electric field is

torque = E P sin(theta), where 'theta' is the angle

a) in parallel position theta = 0 , so that torque = zero

b) in perpendicular position theta= 90 degree and sin(90) = 1

,so that, torque = EP sin 90 = 4.5x10^6 x 2x1x10^-9x2x1.6x10^-19

= 2.88 x 10^-21 N -m

c) in antiparallel position theta = 180 and as sin180 = zero

, the torque will also be zero.