Because the specimen is very small with a light microscope
The magnetic field strength of a very long current-carrying wire is proportional to the inverse of the distance from the wire. The farther you go from the wire, the weaker the magnetic field becomes.
B ∝ 1/d
B = magnetic field strength, d = distance from wire
Calculate the scaling factor for d required to change B from 25μT to 2.8μT:
2.8μT/25μT = 1/k
k = 8.9
You must go to a distance of 8.9d to observe a magnetic field strength of 2.8μT
Answer: The answer is the masses of the objects and the distance between them
Explanation: Gravity is affected by mass and distance between two objects becuase if and object is too far the force of gravity will not be strong. The larger the object, the stronger the force of gravity will be.