Dipped in water
Dipped in sand
Attached to an iron piece
Heated to high temperature
Step 1: Understanding Magnetic Property Loss Magnetic materials exhibit magnetism due to the alignment of their atomic dipoles. However, when subjected to high temperatures, these dipoles gain excessive thermal energy and start to misalign, leading to a loss of magnetization.
Step 2: Curie Temperature Concept The temperature beyond which a magnetic material loses its permanent magnetism is called the Curie Temperature. Above this temperature, the material transitions from a ferromagnetic to a paramagnetic state, losing its strong magnetic properties.
Step 3: Evaluating the Given Options - Dipping in water (Incorrect): Water does not affect the internal magnetic alignment of a material.
- Dipping in sand (Incorrect): Sand particles do not alter the magnetic domains of a material.
- Attaching to an iron piece (Incorrect): This only affects external interactions but does not remove the intrinsic magnetism.
- Heating to high temperature (Correct): Heat energy disrupts the alignment of magnetic dipoles, causing the material to lose its magnetization.
Step 4: Conclusion Thus, a magnetic material loses its magnetic property when it is heated to a high temperature.
A conducting bar moves on two conducting rails as shown in the figure. A constant magnetic field \( B \) exists into the page. The bar starts to move from the vertex at time \( t = 0 \) with a constant velocity. If the induced EMF is \( E \propto t^n \), then the value of \( n \) is _____.
The value of shunt resistance that allows only 10% of the main current through the galvanometer of resistance \( 99 \Omega \) is:
A current of \(6A\) enters one corner \(P\) of an equilateral triangle \(PQR\) having three wires of resistance \(2 \Omega\) each and leaves by the corner \(R\) as shown in figure. Then the currents \(I_1\) and \(I_2\) are respectively