An electric dipoel consists of two equal and opposite charges placed 2 cm apart. When the dipole is placed in a uniform electric field of strength `10^5NC^-1`, it experiences a maximum torque of `0.2 xx 10^-3Nm`. Find the magnitude of each charge.

Explanation

`2a = 2cm ` = Dipole length
`E = 10^5 NC^(-1)`
`tau_("maxi") = 0.2 xx 10^(-3) Nm`
`tau_("maxi") = PE = q(2a)E`
`q = (tau_("maxi"))/((2a)E)`
`q = (0.2 xx 10^(-3))/(2 xx 10^(-2) xx 10^5)`
`q = 0.1 xx 10^(-6) = 0.1 mu c`
So magnitude of each charge = `0.1 mu C`.