List of top Physics Questions on Magnetism and matter asked in BHU UET

A dip needle arranged to move freely in the magnetic meridian dips by an angle $\theta$. If the vertical plane in which the needle moves is rotated through an angle $\alpha$ to the magnetic meridian, then the needle will dip by an angle

If the total magnetic field due to earth is $28 \,Am$, then the total magnetic induction due to earth is

A bar magnet has a coercively $ 4\times {{10}^{3}}A{{m}^{-1}} $ . It is desired to demagnetize it by inserting it inside a solenoid $12\, cm$ long and having $60$ turns. The current carried by the solenoid should be:

Each atom of an iron bar $(5\, cm \times 1\, cm \times 1\, cm )$ has a magnetic moment $1.8 \times 10^{-23}\, Am ^{2}$. Knowing that the density of iron is $7.78 \times 10^{3}\, kg\, m ^{-3}$, atomic weight is $56$ and Avogadro's number is $6.02 \times 10^{23}$ the magnetic moment of bar in the state of magnetic saturation will be