The answer to this question is b
Answer:
Explanation:
Volume of the insulating shell is,

Charge density of the shell is,

Here, 

B)
The electric field is 
For 0 <r<R the electric field is zero, because the electric field inside the conductor is zero.
C)
For R <r <2R According to gauss law

substitute 

D)
The net charge enclosed for each r in this range is positive and the electric field is outward
E)
For r>2R
Charge enclosed is zero, so electric field is zero
The fragment of an asteroid or any interplanetary material is known as A. METEROID
Answer:
It is always said that mass is same everywhere.
Answer:
A model is defined as a structure used to represent an object, usually of a different scale.
Explanation:
In quantum mechanics and particle physics, many of the particles are subatomic, meaning that they are smaller than atoms. This is where a model would be useful. A model could help people to visualise what the particle looks like, and in general would make it easier to understand the behaviour of such a particle.