Advertisements
Advertisements
प्रश्न
Why should the material used for making permanent magnets have high coercivity?
Advertisements
उत्तर
Materials having high coercivity are used to make permanent magnets because magnetisation of such materials does not get affected by stray magnetic fields or high temperature.
APPEARS IN
संबंधित प्रश्न
State two advantages of an electromagnet over a permanent magnet.
What are permanent magnets? Give one example ?
Can we have a single north pole, or a single south pole?
Consider the situation of the previous problem. The directions of the magnetic field due to the dipole are opposite at
(a) P1 and P2
(b) Q1 and Q2
(c) P1 and Q1
(d) P2 and Q2
To measure the magnetic moment of a bar magnet, one may use
(a) a tangent galvanometer
(b) a deflection galvanometer if the earth's horizontal field is known
(c) an oscillation magnetometer if the earth's horizontal field is known
(d) both deflection and oscillation magnetometer if the earth's horizontal field is not known
Why is it not possible to make permanent magnets from paramagnetic materials?
The magnetic moment of the assumed dipole at the earth's centre is 8.0 × 1022 A m2. Calculate the magnetic field B at the geomagnetic poles of the earth. Radius of the earth is 6400 km.
A deflection magnetometer is placed with its arms in north-south direction. How and where should a short magnet having M/BH = 40 A m2 T−1 be placed so that the needle can stay in any position?
