Advertisements
Advertisements
प्रश्न
A meter gauge train is heading north with speed 54 km/hr in earth's magnetic field 3 x 10-4T. The e.m.f. induced across the axle joining the wheels is ..........
(a) 0.45 mV
(b) 4.5 mV
(c) 45 mV
(d) 450 m V
Advertisements
उत्तर
(b) 4.5 mV
e = vlb
`= 54 xx 5/18 xx 1 xx 3 xx 10^(-4)`
`= 45 xx 10^(-4) = 4.5 mV`
APPEARS IN
संबंधित प्रश्न
Which of the following substances is ductile?
An iron rod of the area of cross-section 0.1m2 is subjected to a magnetizing field of 1000 A/m. Calculate the magnetic permeability of the iron rod. [Magnetic susceptibility of iron = 59.9, magnetic permeability of vacuum = 4π x 10-7 S. I. unit]
Distinguish between diamagnetic and paramagnetic substances.
The magnetic susceptibility of annealed iron at saturation is 4224. Find the permeability of
annealed iron at saturation. (μ0 = 4Π × 10−7 SI unit)
The susceptibility of a magnetic material is 0·9853. Identify the type of magnetic material. Draw the modification of the field pattern on keeping a piece of this material in a uniform magnetic field.
Which of the following substances are para-magnetic?
Bi, Al, Cu, Ca, Pb, Ni
The relative magnetic permeability of a magnetic material is 800. Identify the nature of magnetic material and state its two properties.
The magnetic susceptibility of platinum is 0.0001. It's relative permeability is:
Two substances A and B have their relative permeability slightly greater and slightly less than 1 respectively. What do you conclude about A and B as far as their magnetic materials are concerned?
Choose the correct option:
A magnetising field of 360 Am−1 produces a magnetic flux density (B) = 0.6T in a ferromagnetic material. What is its permeability in Tm A−1?
What happens to a ferromagnetic material when its temperature increases above curie temperature?
The susceptibility of a paramagnetic material is χ at 27° C. At what temperature its susceptibility be χ/3?
Two identical bar magnets each of magnetic moment M, separated by some distance are kept perpendicular to each other. The magnetic induction at a point at the same distance d from the centre of magnets, is (µ0 = permeability of free space)
A domain in a ferromagnetic substance is in the form of a cube of side 1 µm. If it contains 8 × 1010 atoms and each atomic dipole has a dipole moment of 9 × 10-24 Am2 then the magnetisation of the domain is ______.
All atoms of a magnetic substance have a resultant magnetic moment even in absence of external magnetic field. The substance is ______.
Magnetic material can be easily magnetized if magnetic susceptibility is ______.
If a magnetic field is applied to a liquid in one arm of a narrow U-tube, the liquid level in that arm is lowered. The liquid in U-tube arm is ______.
The materials having negative magnetic susceptibility are ____________.
The magnetic property of magnetic substance is associated with ____________.
A sphere of gold when brought towards a powerful magnet experiences ____________.
A domain in a ferromagnetic substance is in the form of a cube of side length 1 µm. If it contains 6 x 1010 atoms and each atomic dipole has a dipole moment of 7 x 10-24 Am2, then magnetization of the domain is ____________.
A short bar magnet has a magnetic moment of 0.48 J T−1. Give the direction and magnitude of the magnetic field produced by the magnet at a distance of 10 cm from the centre of the magnet on
- the axis,
- the equatorial lines (normal bisector) of the magnet.
Magnetic field lines are always nearly normal to the surface of a ferromagnet at every point. (This fact is analogous to the static electric field lines being normal to the surface of a conductor at every point.) Why?
Would the maximum possible magnetisation of a paramagnetic sample be of the same order of magnitude as the magnetisation of a ferromagnet?
Nickel shows ferromagnetic property at room temperature. If the temperature is increased beyond curie temperature, then it will show ______.
The given figure represents a material which is ______.
Assertion: The ferromagnetic substance do not obey Curie’s law.
Reason: At Curie point a ferromagnetic substance start behaving as a paramagnetic substance.
Assertion: A paramagnetic sample display greater magnetisation (for the same magnetic field) when cooled.
Reason: The magnetisation does not depend on temperature.
The magnetic susceptibility is negative for ______.
Two identical bar magnets are fixed with their centres at a distance d apart. A stationary charge Q is placed at P in between the gap of the two magnets at a distance D from the centre O as shown in the figure. The force on the charge Q is ______.
The magnetic susceptibility for diamagnetic materials is ______.
When a ferromagnetic material is created above its curie temperature
Earth's magnetic field analyses has a horizontal component except at:-
A hydrogen atom is paramagnetic. A hydrogen molecule is
The universal property of all substances is ______.
S is the surface of a lump of magnetic material.
- Lines of B are necessarily continuous across S.
- Some lines of B must be discontinuous across S.
- Lines of H are necessarily continuous across S.
- Lines of H cannot all be continuous across S.
Essential difference between electrostatic shielding by a conducting shell and magnetostatic shielding is due to ______.
- electrostatic field lines can end on charges and conductors have free charges.
- lines of B can also end but conductors cannot end them.
- lines of B cannot end on any material and perfect shielding is not possible.
- shells of high permeability materials can be used to divert lines of B from the interior region.
Explain quantitatively the order of magnitude difference between the diamagnetic susceptibility of N2 (~5 × 10–9) (at STP) and Cu (~10–5).
From molecular view point, discuss the temperature dependence of susceptibility for diamagnetism, paramagnetism and ferromagnetism.
- Assertion (A): Diamagnetic substances exhibit magnetism.
- Reason (R): Diamagnetic materials do not have a permanent magnetic dipole moment.
Explain the origin of paramagnetism on the basis of atomic structure.
Magnetic susceptibility of a diamagnetic substance ______.
