xvxvxv

Just I have some questions 

First of all if there is no point charge inside the cavity of the sphere the inner radius will carry any charge! 

yes .. the result would be the same .. but they made a mistake when they wrote from the write .. 

Thank you Alan .. ~ 

oooohhhhhhh right .... hhhhhhh I felt for a moment that I'm squint  

thank you CPhill 

well but what do you mean by anti-clockwise moment 

I just know that moment is $$P = qd$$ .. 

and P is a vector from the negative charge of the dipole do the positive charge . 

and torque = $$P.E sin$$θ

and we use the right hand rule to determine the direction of the torque . 

Now we didn't use the electric dipole moment (  P ) 

so how we determined the direction of the tourqe 

I'am sorry for askin you alot of question 

but really I want to make it clear for me 

But in the solution manual of the booke ! why they said that the x component produce torque ? 

but why the horizontal component of the force will not give rise to a torque ! 

I mean waht is the relation ship between force and torque ?

Anyone ?! 

yes now its very clear .. 

thank you =) 

it will be -cscθ +c 

right  ? 

I tried but I can't .. ><