I’m going to use molasses as an example of a substance.
The mass and volume both change when changing the amount of molasses.
However, the density does not change. This is because the mass and volume increase at the same rate/proportion!
Even though there is more molasses (mass) in test tube A, the molasses also takes up more space (volume). Therefore, the spacing between those tiny particles that make up the molasses is constant (does not change).
The size or amount of a material/substance does not affect its density.
Answer:
E=
Explanation:
We are given that
Charge on ring= Q
Radius of ring=a
We have to find the magnitude of electric filed on the axis at distance a from the ring's center.
We know that the electric field at distance x from the center of ring of radius R is given by

Substitute x=a and R=a
Then, we get




Where K=
Hence, the magnitude of the electric filed due to charged ring on the axis of ring at distance a from the ring's center=