Download App

Question Bank [ 2022 ] — Physics STD 12 Science — Question

Maharashtra BoardEnglish MediumSTD 12 SciencePhysicsQuestion Bank [ 2022 ]4 Marks
Question
Define magnetization. State its SI unit and dimensions. Derive the relation between magnetic field intensity(H) and magnetization(M) for a magnetic material placed in a magnetic field.
✓

Answer

i. The ratio of magnetic moment to the volume of the material is called magnetization.
ii. Unit: $Am ^{-1}$ in $SI$ system.
iii. Dimensions: $\left[ M ^0 L ^{-1} T ^0 I ^1\right]$
iv. Relation between magnetic field intensity $( H )$ and magnetization(M):
a. Consider a magnetic material (rod) placed in a magnetizing field (solenoid with $n$ turns per unit length and carrying current I).
b. The magnetic field inside the solenoid is given by, $B _0=\mu_0 nl \ldots .(1)$
Where $\mu_0=$ permeability of free space.
c. The magnetic field inside the rod is given as, $B _{ m }=\mu_0 M \ldots$...(2)
Where $M=$ magnetization of the material
d. The net magnetic field inside the rod is expressed as,
$ B = B _0+ B _{ m } \ldots .(3)$
$\therefore B =\mu_0 nl +\mu_0 M$
$\therefore B =\mu_0 H +\mu_0 M $
Where $H = nl =$ Magnetic field intensity
$ \therefore B=\mu_0(H+M)$
$\therefore H=\frac{B}{\mu_0}-M . $
e. Equation (4) shows that the magnetic field (B) induced in the material depends on magnetic field intensity $( H )$ and magnetization (M).

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

Explore more

More "Answer the following in Detail" from Question Bank [ 2022 ]→Question Bank [ 2022 ] — all question types→Physics STD 12 Science question papers→Maharashtra Board STD 12 Science question papers→Maharashtra Board question paper generator→

Similar questions

Write a note on the major diatonic scale.
OR
Explain what is a musical scale.
→
A solid cylinder, of mass $2 \mathrm{~kg}$ and radius $0.1 \mathrm{~m}$, rolls down an inclined plane of height $3 \mathrm{~m}$. Calculate its rotational energy when it reaches the foot of the plane.
→
A satellite moves around the Earth in an elliptical orbit such that at perigee (closest approach) it is two Earth radii above the Earth's surface. At apogee (farthest position), it travels with one-fourth the speed it has at perigee. In terms of the Earth's radius R, what is the maximum distance of the satellite from the Earth's surface?
→
State first law of thermodynamics.
→
Explain a streamline and streamline flow.
→
The pressure of a gas in a 0.1 litre container is $200 \mathrm{kPa}$ and the KE per molecule is $6 \times 10^{-21} \mathrm{~J}$. Find the number of gas molecules in the container. How many moles are in the container?
[Avogadro number $=6.022 \times 10^{23} \mathrm{~mol}^{-1}$ ]
→
What is an isothermal process? Obtain an expression for the work done by a gas in an isothermal process.
→
Explain De Broglie’s Hypothesis.
→
What is an open tube manometer? Briefly describe its function with a neat diagram.
→
Briefly describe the construction of a simple ac generator. Obtain an expression for the emf induced in a coil rotating with a uniform angular velocity in a uniform magnetic field. Show graphically the variation of the emf with time (t). OR Describe the construction of a simple ac generator and explain its working.
→