(b) With a current of 0.38 A, the average velocity of an electron in the wire is 5.5  10-6 m s-1 and the average magnetic force on one electron is 1.4  10-25 N. Calculate the flux density B of the magnetic field.

B = 0.159 T

Explanation:

Given that,

Current, I = 0.38 A

The average velocity of the electron,

The average magnetic force on the electron,

We need to find the flux density B of the magnetic field. We know that the magnetic force is given by :

Put all the values,

So, the required flux density of the magnetic field is 0.159 T.

answer: the rock sample is a sedimentary rock.

explanation:

it is given that:

mass of rock sample, m = 2.7 g

volume of rock sample,

so, density of rock sample will be

since, the density of rock sample is . hence, the rock sample is a sedimentary rock, whose densities varies between .

i think the answer is a, hope this is right, that would be my best guess.