List of top Physics Questions on Magnetic properties of materials

Match List I with List II.

List I (Material)		List II (Subsceptibility(χ))
A.	Diamagnetic	I.	χ = 0
B.	Ferromagnetic	II.	0 > χ ≥ –1
C.	Paramagnetic	III.	χ >> 1
D.	Non-magnetic	IV.	0 < χ < ε (a small positive number)

Choose the correct answer from the options given below:

A bar magnet with a magnetic moment 50 $Am ^2$ is placed in parallel position relative to a magnetic field of 0.4T. The amount of required work done in turning the magnet from parallel to antiparallel position relative to the field direction is

A uniform magnetic field b exists in a region. An electron of charge q and mass m moving with velocity v enters the region in a direction perpendicular to the magnetic field. Considering Bohr angular momentum quantization, which of the following statement(s) is/are true?

A compass needle of oscillation magnetometer oscillates 20 times per minute at a place P of dip 30°. The number of oscillations per minute become 10 at another place Q of 60° dip. The ratio of the total magnetic field at the two places (B_Q: B_P) is

In a permanent magnet at room temperature

Coercivity and retentivity of soft iron is

Coercivity and retentivity of soft iron is

The B-H curve for a ferromagnet is shown in the figure. The ferromagnet is placed inside a long solenoid with 1000 turns/cm. The current that should be passed in the solenoid to demagnetise the ferromagnet completely is :

For a permanent magnet, properties of material should be

The magnetic susceptibility is negative for :

The substance magnetite is

Two short bar magnets of length $1\, cm$ each have magnetic moments $1.20 \,Am^2 $ and $1.00 \,Am^2 $ respectively. They are placed on a horizontal table parallel to each other with their $N$ poles pointing towards the south. They have a common magnetic equator and are separated by a distance of $20.0\, cm$. The value of the resultant horizontal magnetic induction at the mid-point $O$ of the line joining their centres is close to (Horizontal component of the earth's magnetic induction is $ 3.6 \times {10}^{-5} W b/m^2$

The electric field intensity just sufficient to balance the earth's gravitational attraction on an electron will be: (given mass and charge of an electron respectively are $9.1 \times 10^{-31}\, kg$ and $\left.1.6 \times 10^{-19} C \right)$.

Two small magnets each of magnetic moment 10 $Am^2$ are placed in end on position 0.1 m apart from their centres. The force acting between them is

Material of permanent magnet has

The magnetic susceptibility of paramagnetic materials is

The magnetic moment of atomic neon is

Nickel shows ferromagnetic property at room temperature. If the temperature is increased beyond Curie temperature, then it will show

Two short bar magnets P and Q are arranged such that their centres are on the X-axis and are separated by a large distance. The magnetic axes of P and Q are along X and Y axes respectively. At a point R, midway between their centres, if B is the magnitude of induction due to Q, the magnitude of total induction at R due to the both magnets is:

Needles $N_{1}, N_2$ and $N_3$ are made of a ferromagnetic, a paramagnetic and a diamagnetic substance respectively. A magnet when brought close to them will:

The magnetic moment has dimensions of:

The .examples of diamagnetic, paramagnetic and ferromagnetic materials are respectively:

The diamagnetic species is

The materials suitable for making electromagnets should have