If one reverse the orientation of a permanent magnet ITS MAGNETIZATION WILL BE PERMANENTLY REVERSED. This is because, the magnetic domains inside the permanent magnet aligned with the new applied field and increase with it while those domains that are anti aligned with that field will shrink.
Answer:(b)
Explanation:
Given
Electric current flowing through the horizontal wire towards the observer's face.
The direction of the magnetic field is given by the right-hand thumb rule, i.e. place the thumb in the direction of current and the wrapping of fingers will give the direction of the magnetic field
the direction of the magnetic field will be counterclockwise as observed by an observer.
Newton’s 2nd law states that Force is equal to
the product of mass (m) and acceleration (a):
F = m a --->
1
While in magnetic forces, force can also be expressed as:
F = q v B --->
2
where,
q = total charge
v = velocity = 45 cm / s = 0.45 m / s
B = the magnetic field = 85 T
First we solve for the total charge, q:
q = 3.8 × 10^-23 g (1 mol / 23 g) (6.022 × 10^23 electrons / mol) (1.602 ×
10^-19 C / electron)
q = 1.594 × 10^-19 C
We equate equations 1 and 2 then solve for acceleration a:
m a = q v B
a = q v B / m
a = [1.594 × 10^-19 C * 0.45 m / s * 85 T] / 3.8 × 10-26 kg
a = 160,437,862.2 m/s^2
Therefore the maximum acceleration of Na ions is about 160 × 10^6 m/s^2.
