Statement —I: Electromagnets are made of soft iron.
Statement —II: Soft iron has lower permeability and high retentivity.
Choose the correct option related to statements.
Statement —II: Soft iron has lower permeability and high retentivity.
Choose the correct option related to statements.
- Statement — I is true but Statement — II is false
- Statement — I is false but Statement — II is true
- Statement — I is false and Statement — II is also false
- Statement —I is true and Statement —II is also true
The Correct Option is B
Solution and Explanation
Soft iron is used in electromagnets due to its high permeability, which allows magnetic lines of force to pass through it easily, and its low retentivity, which ensures it does not retain significant magnetism when the external field is removed.
Hence: Assertion \( A \) is correct because soft iron is the material of choice for electromagnets.
Reason \( R \) is correct because the properties of high permeability and low retentivity make soft iron ideal for electromagnets. Furthermore, \( R \) correctly explains \( A \).
Final Answer: Both statements are correct, and \( R \) is the correct explanation of \( A \): \[ \boxed{\text{(2) Both \( A \) and \( R \) are correct and \( R \) is the correct explanation of \( A \)}}. \]
Top Questions on Magnetism and matter
- An inductor stores \(16\,\text{J}\) of magnetic field energy and dissipates \(32\,\text{W}\) of thermal energy due to its resistance when an alternating current of \(2\,\text{A}\) (rms) and frequency \(50\,\text{Hz}\) flows through it. The ratio of inductive reactance to resistance is _______. \((\pi=3.14)\) Given: \[ U=16\,\text{J},\quad P=32\,\text{W},\quad I=2\,\text{A},\quad f=50\,\text{Hz} \]
- JEE Main - 2026
- Physics
- Magnetism and matter
- A long cylindrical conductor with large cross section carries an electric current distributed uniformly over its cross-section. Magnetic field due to this current is:
[A.] maximum at either end of the conductor
[B.] maximum at the axis of the conductor and minimum at the midpoint
[C.] minimum at the surface of the conductor
[D.] minimum at the axis of the conductor
[E.] same at all points in the cross-section of the conductor
Choose the correct answer from the options given below:- JEE Main - 2026
- Physics
- Magnetism and matter
- A plane electromagnetic wave is moving in free space with velocity \[ c=3\times10^{8}\ \text{m/s} \] and its electric field is given as \[ \vec E = 54\sin(kz-\omega t)\,\hat{j}\ \text{V/m}, \] where \(\hat{j}\) is the unit vector along the \(y\)-axis. The magnetic field \(\vec B\) of the wave is:
- JEE Main - 2026
- Physics
- Magnetism and matter
A current-carrying coil is placed in an external uniform magnetic field. The coil is free to turn in the magnetic field. What is the net force acting on the coil? Obtain the orientation of the coil in stable equilibrium. Show that in this orientation the flux of the total field (field produced by the loop + external field) through the coil is maximum.
- CBSE CLASS XII - 2025
- Physics
- Magnetism and matter
- When an external magnetic field of strength \(1.5 \times 10^{-3}\) A/m is applied to a rock sample, the measured intensity of magnetization is \(0.5 \times 10^{-3}\) A/m. The magnetic susceptibility of this rock is ________ (Round off to two decimal places).
- GATE GG - 2025
- Geology and Geophysics
- Magnetism and matter
Questions Asked in JEE Main exam
Which one of the following graphs accurately represents the plot of partial pressure of CS₂ vs its mole fraction in a mixture of acetone and CS₂ at constant temperature?
- JEE Main - 2026
- Organic Chemistry
- For two identical cells each having emf \(E\) and internal resistance \(r\), the current through an external resistor of \(6\,\Omega\) is the same when the cells are connected in series as well as in parallel. The value of the internal resistance \(r\) is ________ \(\Omega\).
- JEE Main - 2026
- Current electricity
- For three unit vectors \( \vec a, \vec b, \vec c \) satisfying \[ |\vec a-\vec b|^2 + |\vec b-\vec c|^2 + |\vec c-\vec a|^2 = 9 \] and \[ |2\vec a + k\vec b + k\vec c| = 3, \] the positive value of \( k \) is:
- JEE Main - 2026
- Vector Algebra
In the given figure, the blocks $A$, $B$ and $C$ weigh $4\,\text{kg}$, $6\,\text{kg}$ and $8\,\text{kg}$ respectively. The coefficient of sliding friction between any two surfaces is $0.5$. The force $\vec{F}$ required to slide the block $C$ with constant speed is ___ N.
(Given: $g = 10\,\text{m s}^{-2}$)
- JEE Main - 2026
- Rotational Mechanics
- The system of linear equations
$x + y + z = 6$
$2x + 5y + az = 36$
$x + 2y + 3z = b$
has- JEE Main - 2026
- Matrices and Determinants
Concepts Used:
Magnetism & Matter
Magnets are used in many devices like electric bells, telephones, radio, loudspeakers, motors, fans, screwdrivers, lifting heavy iron loads, super-fast trains, especially in foreign countries, refrigerators, etc.
Magnetite is the world’s first magnet. This is also called a natural magnet. Though magnets occur naturally, we can also impart magnetic properties to a substance. It would be an artificial magnet in that case.
Read More: Magnetism and Matter
Some of the properties of the magnetic field lines are:
- The lines and continuous and outside the magnet, the field lines originate from the North pole and terminate at the South pole
- They form closed loops traversing inside the magnet.
- But here the lines seem to originate from the South pole and terminate at the North pole to form closed loops.
- More number of close lines indicate a stronger magnetic field
- The lines do not intersect each other
- The tangent drawn at the field line gives the direction of the field at that point.