A large sheet carries uniform surface charge density sigma A rod of length 2l has a linear charge density lamda - Science - Electricity and Circuits

Question

A large sheet carries uniform surface charge density sigma A rod of
length 2l has a linear charge density lamda on one half and -lama
on the other The rod is hinged at mid point O and makes theta with
normal to the sheet The torque experienced by the rod is

Govind · Accepted Answer

Hi,

Elementary length = Eλdx

Now, torque = Eλdxxsinθ

τ=∫0lEλxdxsinθ⇒τ=λEsinθl22
Thus, we get λEsinθl2/2
similarly for lower part torque will be
λEsinθl2/2
so net torque = λEsinθl2
E=σ/2ε0
so τ =
λEsinθl2/2ε0

A large sheet carries uniform surface charge density sigma.A rod of length 2l has a linear charge density lamda on one half and -lama on the other.The rod is hinged at mid point O and makes theta with normal to the sheet.The torque experienced by the rod is