In end on and broadside on position of a deflection magnetometer, if θ₁ and θ₂ are the deflections produced by short magnets at equal distances, then tan θ₁/ tanθ₂ is

2 : 1
1 : 2
1 : 1
None of these

Solution

\(\frac{tan\Theta _{1}}{tan\Theta _{2}}=\frac{2}{1}\)

At a certain place, horizontal component is √3 times the vertical component. The angle of dip at this place is

zero
π/3
π/6
None of these

Solution

The magnetic moment of a magnet is 0.1 amp × m². It is suspended in a magnetic field of intensity 3 × 10^-4weber/m².The couple acting upon it when deflected by 30º from the magnetic field is

1 × 10^–5N m
1.5 × 10^–5N m
2 × 10^–5N m
2.5 × 10^–5N m

Solution

τ= MB sin θ= 0.1 × 3 × 10^–4 sin 30º

or τ = 1.5 × 10^–5N–m

The magnet of pole strength m and magnetic moment M is cut into two pieces along its axis.Its pole strength and magnetic moment now becomes

^m⁄₂,^M⁄₂
m,^M⁄₂
^m⁄₂,M
m,M

Solution

When cut along the axis, area of cross-section becomes half. Therefore,pole strength is halved and M = m (2 l), is also halved.

Two isolated point poles of strength 30 A-m and 60 A-m are placed at a distance of 0.3m. The force of repulsion is

2 × 10^–3 N
2 × 10^–4 N
2 × 10⁵ N
2 × 10^-5 N

Solution

When a ferromagnetic material is heated to temperature above its Curie temperature, the material

is permanently magnetized
remains ferromagnetic
behaves like a diamagnetic material
behaves like a paramagnetic material

The line on the earth surface joining the point where the field is horizontal, is called

magnetic equato
magnetic line
magnetic axis
magnetic inertia

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

anti ferromagnetism
no magnetic property
diamagnetism
paramagnetism

Current i is flowing in a coil of area A and number of turns N,then magnetic moment of the coil, M is

NiA
^Ni⁄_A
^Ni⁄_√A
N²Ai

The main difference between electric lines of force and magnetic lines of force is

electric lines of force are closed curves where as magnetic lines of force are open curves
electric lines of force are open curves whereas magnetic lines of force are closed curves
magnetic lines of force cut each other whereas electric lines of force do not cut
electric lines of force cut each other whereas magnetic lines of force do not cut

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