MCQ
Permanent magnets are the substances having the property of:
  • Ferromagnetism at room temperature for a long period of time.
  • B
    Paramagnetism at room temperature for a long period of time.
  • C
    Anti ferromagnetism at room temperature for a long period of time.
  • D
    Diamagnetism at room temperature for a long period of time.

Answer

Correct option: A.
Ferromagnetism at room temperature for a long period of time.

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

The magnetic susceptibility does not depend upon the temperature in
The refractive index of a piece of transparent quartz is the greatest for
A condenser of capacity $C_1$ is charged to a potential $V_0$. ThVe electrostatic energy stored in it is $U_0$. It is connected to another uncharged condenser of capacity $C_2$ in parallel. The energy dissipated in the process is
Electron beam used in an electron microscope, when accelerated by a voltage of $20\,kV$. has a de-Broglie wavelength of $\lambda_0$. If the voltage is increased to $40\,kV$. then the de-Broglie wavelength associated with the electron beam would be:
A charge particle is moving in a uniform magnetic field $(2 \hat{i}+3 \hat{j}) T$. If it has an acceleration of $(\alpha \hat{i}-4 \hat{j}) m / s ^{2}$, then the value of $\alpha$ will be.
In the figure shown in $YDSE$, $a$ parallel beam of light is incident on the slit from $a$ medium of refractive index $n_1$. The wavelength of light in this medium is $\lambda_1$. $A$ transparent slab of thickness $‘t’$ and refractive index $n_3$ is put infront of one slit. The medium between the screen and the plane of the slits is $n_2.$ The phase difference between the light waves reaching point $‘O’$ (symmetrical, relative to the slits) is :
If the length of potentiometer wire is increased, then the length of the previously obtained balance point will:
A long solenoid has $1000$ turns per metre and carries a current of $1\,\, A.$ It has a soft iron core of $μ_T = 1000.$ The core is heated beyond the Curie temperature, $T_C.$ 
The minimum number of capacitors each of $2$ $\mu F$ required to make a circuit with an equivalent capacitance $5$ $\mu F$ is
The two slits at a distance of 1 mm are illuminated by the light of wavelength $6.5 \times 10^{-7} m$. The interference fringes are observed on a screen placed at a distance of 1m. The distance between third dark fringe and fifth bright fringe will be