If you apply a little bit of force, one will move easier than the other since it is lighter.
Answer:
B'=1.935 T
Explanation:
Given that
magnetic field ,B= 0.645 T
We know that magnetic filed in the solenoid is given as
![B=\mu _0 n\ I](https://tex.z-dn.net/?f=B%3D%5Cmu%20_0%20n%5C%20I%20)
I=Current
n=Number of turn per unit length
μ0 =magnetic permeability
Now when the current increased by 3 factors
I'=3 I
Then the magnetic filed
![B'=\mu _0 n\ I'](https://tex.z-dn.net/?f=B%27%3D%5Cmu%20_0%20n%5C%20I%27)
![B'=\mu _0 n\ (3I)](https://tex.z-dn.net/?f=B%27%3D%5Cmu%20_0%20n%5C%20%283I%29)
B'=3 B
That is why
B' = 3 x 0.645 T
B'=1.935 T
Therefore the new magnetic filed will be 1.935 T.
Iron oxide = small region within a magnet
drop or hammer =man-made magnet
strength decreases rapidly with distance lines of force
BBBBBBBB!!!!! ATOMIC MASSES :D