MCQ
The magnet can be completely demagnetized by
  • A
    Breaking the magnet into small pieces
  • B
    Heating it slightly
  • C
    Droping it into ice cold water
  • A reverse field of appropriate strength

Answer

Correct option: D.
A reverse field of appropriate strength
(d)

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

An electromagnetic wave going through vacuum is described by $E=E_0 \sin (k x-\omega t) ; \quad B=B_0 \sin (k x-\omega t)$. Which of the following equation is true
A conducting rod of length $2 /$ is rotating with constant angular speed $\omega$ about its perpendicular bisector. A uniform magnetic field $\vec{B}$ exists parallel to the axis of rotation. The e.m.f. induced between two ends of the rod isImage
Standing waves are produced in a $10 \mathrm{~m}$ long stretched string. If the string vibrates in $5$ segments and the wave velocity is $20 \mathrm{~m} / \mathrm{s}$, the frequency is
Density of rubber is $d$. A thick rubber cord of length $L$ and crosssection area $A$ undergoes elongation under its own weight on suspending it. This elongation is proportional to
The range of a particle when launched at an angle of $15^{\circ}$ with the horizontal is $1.5 \ km$. What is the range of the projectile when launched at an angle of $45^{\circ}$ to the horizontal
We wish to see inside an atom. Assuming the atom to have a diameter of $100\  \mathrm{pm}$, this means that one must be able to resolved a width of say $10$ p.m. If an electron microscope is used, the minimum electron energy required is about
The resistivity of a potentiometer wire is $40 \times 10^{-8} \mathrm{ohm}-\mathrm{m}$ and its area of cross-section is $8 \times 10^{-6} \mathrm{~m}^2$. If $0.2\  \mathrm{amp}$ current is flowing through the wire, the potential gradient will be
Dimensional formula of heat energy is
The figure illustrate how $B$, the flux density inside a sample of unmagnetised ferromagnetic material varies with $B$, the magnetic flux density in which the sample is kept. For the sample to be suitable for making a permanent magnetImage
A step index fibre has a relative refractive index of $0.88 \%$. What is the critical angle at the corecladding interface