An electric dipole having each charge of magnitude 2 C is placed in an electric field of intensity 8 10⁺⁴ ~N / C . If the maximum torque acting on the dipole is 4 10⁻³ ~N - m , the length of the dipole is

Step-by-step solution

The maximum torque _ max on an electric dipole in a uniform electric field E is given by _ max = pE , where p is the electric dipole moment. Applying this to the known values _ max = 4 10⁻³ N m and E = 8 10^4 N/C yields p = _ max /E = 5 10⁻⁸ C m . Since p = q(2l) with q = 2 10⁻⁶ C , the dipole length is 2l = p/q = 2.5 10⁻² m . Converting to millimeters gives 2l = 25 mm . Final answer: 25 mm