MCQ
Alnico is used for making permanent magnets because it has:
- ✓High coercivity and high retentivity.
- BHigh coercivity and low retentivity.
- CLow coercivity and low retentivity.
- DLow coercivity and high retentivity.
✓
Answer
Correct option: A.
High coercivity and high retentivity.
Alnico is used for making permanent magnet because it can be easily magnetised in external magnetic field and It will not lose its magnetic property due to its high coercivity and low retentivity.
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
Two parallel, long wires are kept $0.20\,m$ apart in vacuum, each carrying current of $x$ in the same direction. If the force of attraction per meter of each wire is $2 \times 10^{-6}\,N$, then the value of $x$ is approximately
→A $25\, watt$, $220\, volt$ bulb and a $100\, watt$, $220\, volt$ bulb are connected in parallel across a $220\, volt$ line. Which bulb will glow more brightly
→In a region of space the electric field is given by $\vec E = 8\hat i + 4\hat j+ 3\hat k$. The electric flux through a surface of area $100\, units$ in the $x-y$ plane is....$units$
→A ray of light originates from inside a glass slab and is incident on its inner surface at an angle $\theta$ as shown below. In this experiment, the location $x$ of the spot where the ray hits the screen is recorded. Which of the following correctly shows the plot of variation of $x$ with the angle $\theta$ ?
→On a hypotenuse of a right angle prism $\left(30^{\circ}-60^{\circ}\right.$ $-90^{\circ}$ ) of refractive index $1.50$, a drop of liquid is placed as shown in figure. Light is allowed to fall normally on the short face of the prism. In order that the ray of light may get totally reflected, the maximum value of refractive index is:
→The ratio of the magnetic field at the centre of a current carrying coil of the radius $a$ and at a distance ‘$a$’ from centre of the coil and perpendicular to the axis of coil is
→The minimum energy required to remove an electron is called
The nuclear fusion reaction between deuterium and tritium takes place:
A current of 1 ampere is passed through a straight wire of length 2.0 metres. The magnetic field at a point in air at a distance of 3 metres from either end of wire and lying on the axis of wire will be
In a semiconductor diode, the reverse biased current is due to drift of free electrons and holes caused by