Ch 5. Magnetism And Matter Flashcards
The radius of a circular current loop is made double and the current is made half. The magnetic moment of the loop will become
Doubled
Magnetic moment of the earth is
8.0 × 10²² JT⁻¹
Nickel is
Ferromagnetic
The angle between magnetic meridian and geographical meridian is called
Declination
SI unit of magnetic pole strength is
A . m
The torque ( τ ) experienced by a current - loop of magnetic moment (M) placed in magnetic field (B) is
τ = M × B
A bar magnet of magnetic moment M is cut into two parts of equal length. The magnetic moment of either part is
M/2
Magnetic dipole moment is a vector quantity directed from
South to North pole
A wire of magnetic dipole moment M and length L is bent into shape of a semicircle of radius r. What will be its new dipole moment?
2M/π
When the intensity of magnetic field is increased four times, the time-period of suspended magnetic needle becomes
Half
SI unit of magnetic moment is
Am²
SI unit of pole strength is
Am
Which of the following is correct for tangent law?
B = Bh tan θ
h neeche
Work done in the deflection of a magnet in a uniform magnetic field is
W = MB (1 - Cos θ)
Electromagnetic moment of current carrying coil is
m = NI A
Which of the following is correct for short magnet?
(B) axial = 2(B) equatorial
Expression for the time-period of a magnet oscillating in a uniform magnetic field is
T = 2π √I/MBh
Neeche h
The value of angle of dip at magnetic pole of the Earth is
90 Degree
The value of magnetic susceptibility of vacuum is
Zero
Which of the following relation is correct for permeability?
µ = B/H
If B is Earth’s magnetic field in magnetic meridian, δ is angle of dip, Bh is horizontal component of B and Bv is vertical component of B, then which of the following relation is correct?
Neeche h aur v
Bh = B cos δ
Neeche h
On going from North pole to equator, the value of angle of dip
Decreases
The relation between geometrical length (Lg) of a magnet and its magnetic length (Lm) is
Neeche g and m
Lm = 5/6 Lg
Neeche m and g
Iron is
Ferromagnetic
If δ is the angle of dip at a place, then expression for tan δ is
Bv/Bh
Neeche v and h
The susceptibility of paramagnetic substance is
Constant
In Earth’s magnetic field Bh, if the frequency of oscillation of a magnetic needle is n, then
Neeche h
n² ∝ Bh
Neeche h
Dimension of permeability is
MLT⁻²I⁻²
The permeability (µ) of a Ferromagnetic substance is
µ > 1
Nickel is a
Ferromagnetic
Relative permeability is equal to
µ/µ₀ = µr
Neeche r
Which of the following relations is correct?
B² = B²h + B²v
Neeche h and v
The value of B on the surface of the Earth is
10⁻⁵ tesla
Intensity of a magnetising field (H) is equal to
B₀/µ₀
