A straight magnetic strip has a magnetic moment of 44 . If the strip is bent in a semicircular shape, its magnetic moment will be ____ (Given ) [2024]
(28)
Magnetic moment of straight wire
We know that, pole strength
If is the radius of semicircle formed by bending the strip of length then
Distance between the poles;
Hence, new magnetic moment
A bar magnet has total length units and the field point P is at a distance d = 10 units from the centre of the magnet. If the relative uncertainty of length measurement is 1%, then uncertainty of the magnetic field at point P is: [2025]
10%
4%
3%
5%
(2)
Magnetic field at P, , where m is the pole strength
= 1% + 3% = 4%
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : Magnetic monopoles do not exist.
Reason (R) : Magnetic field lines are continuous and form closed loops.
In the light of the above statements, choose the most appropriate answer from the options given below: [2025]
Both (A) and (R) are correct but (R) is not the correct explanation of (A)
(A) is correct but (R) is not correct
Both (A) and (R) are correct and (R) is the correct explanation of (A)
(A) is not correct but (R) is correct
(3)
The magnet does not exist in form of monopole and magnetic lines never intersect, are continuous and form a closed loop. Line initiates from north pole and end to south pole outside while inside vice versa.
It means both statements are correct and reason is also the correct explanation of assertion.
