Question
What is an electromagnet?
✓
Answer
An electromagnet is an insulated coil wrapped around a ferromagnetic core $($usually a soft iron$)$ of high permeability and low retentivity. When a current is passed through the coil$-a$ solenoid or toroid, the ferromagnetic material magnifies the magnetic field of the coil, the magnification factor being the relative permeability$ (\mu / \mu _0)$ of the core. The magnetic field of the current$-$carrying coil magnetizes the core material, thereby producing a much larger field than the coil would produce by itself.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
State postulates of Bohr's atomic model.
Define absolute pressure.
State any two characteristics of angle of contact.
The radius of gyration of a disc about its transverse symmetry axis is $2 \mathrm{~cm}$. Determine its radius of gyration about a diameter.
→Two wires shown in the figure are connected in a series circuit and the same amount of current of $10\ A$ passes through both, but in apposite directions. Separation between the two wires is $8\ mm$ . The length $A B$ is $S =22 cm$. Obtain the direction and magnitude of the magnetic field due to current in wire $2$ on the section $A B$ of wire $1$ . Also obtain the magnitude and direction of the force on wire $1$. $\left[\mu_0=4 \pi \times 10^{-7} T . m / A \right]$
→Green light of wavelength $5100 \mathring A$ from a narrow slit is incident on a double-slit. If the overall separation of $10$ fringes on a screen $200 \ cm$ away from it is $2 \ cm$, find the slit-separation.
→State zeroth law of thermodynamics. What are the limitations of first law of thermodynamics.
Express the mean free path of a gas molecule in terms of pressure and temperature.
The forks, $A$ and $B$, produce 4 beats $/ s$ when sounded together. Fork $A$ is in unison with $30 cm$ length of a sonometer wire and fork $B$ is in unison with $25 cm$ length of the same wire under the same tension. Calculate the frequencies of the forks.
→An electric lamp is connected in series with a capacitor and an AC source is glowing with a certain brightness. How does the brightness of the lamp change on increasing the capacitance ?