Does the center of mass of a body always lie inside the body?
In general centre of mass lie within the body but it may lie outside the system as its the hypothetical point where the entire mass of system is assumed to be concentrated during translational motion.Few examples where the centre of mass lies outside the system are as follows
i don't want this type of answer since i am preparing for iit and so i need a deep explanation of a case where the centre of mass of body lies outside its mass distribution
Yes it can be outside the body. Think of a flat 'V' shaped piece of metal, for example. The centre of mass will be somewhere along the centre line (i.e. somewhere along the line running from the point of the 'V' to the mid-point between the ends of the two arms). You can see straightaway that this centre of mass is outside the body.
How van the force cause the effect? I think we can clear this up by adding a few words to your description: How about this (UPPERCASE letter are my additions)?
The "centre of mass AN IMAGINARY point on the body at which all the individual forces acting on the body if applied would produce the same effect IF THAT IMAGINARY POINT WAS CONNECTED RIGIDLY TO EVERY OTHER POINT ON THE BODY"