Advertisements
Advertisements
Question
Choose the correct option:
A rectangular magnet suspended freely has a period of oscillation equal to T. Now it is broken into two equal halves (each having half of the original length) and one piece is made to oscillate freely. Its period of oscillation is T′, the ratio of T′/T is ______.
Options
`1/(2sqrt2)`
`1/2`
2
`1/4`
Advertisements
Solution
A rectangular magnet suspended freely has a period of oscillation equal to T. Now it is broken into two equal halves (each having half of the original length) and one piece is made to oscillate freely. Its period of oscillation is T′, the ratio of T′/T is `1/2`.
Explanation:
Calculate time period (T) of the complete magnet:
T = `2pi sqrt(I/(mu * B)`
Calculate moment of inertia (I) of the complete magnet:
`I = 1/12 ml^2` .....(1)
Calculate time period (T) of the broken magnet
T' = `2pi sqrt((I"'")/(mu"'" * B)` ......(2)
Calculate moment of inertia (I') of the broken magnet
`I = 1/12 * m/2 * (l/2)^2 = 1/12 (ml^2)/8`
From equation (1):
`I"'" = I/8` also `mu = mu/2`
Substitute moment of inertia (1) in (2):
T' = `2pi sqrt((I"'")/(mu"'" * B)) = 2pi sqrt(I/(8 * mu"'" * B)`
Calaculate ratio `T/T`:
`T/T = (2pisqrt(I/(8 * mu/2 * B)))/(2pi sqrt(I/(mu*B))`
`T/T = 1/2`.
APPEARS IN
RELATED QUESTIONS
Distinguish between ‘paramagnetic’ and ‘ferromagnetic’ substances.
Give any ‘two’ points of differences between diamagnetic and ferromagnetic substances.
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
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.
Which of the following statements is correct for diamagnetic materials?
What happens to a ferromagnetic material when its temperature increases above curie temperature?
Answer in brief.
Discuss the Curie law for paramagnetic material.
A paramagnetic gas has 2.0 × 1026 atoms/m with atomic magnetic dipole moment of 1.5 × 10−23 A m2 each. The gas is at 27°C.
- Find the maximum magnetization intensity of this sample.
- If the gas in this problem is kept in a uniform magnetic field of 3 T, is it possible to achieve saturation magnetization? Why?
For a paramagnetic substance, the magnetic susceptibility is ______.
The susceptibility of a magnetic material is positive and small. The material is ______.
Magnetization of the sample 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 ______.
There are three needles 'N1', 'N2' and 'N3' made of a ferromagnetic, a paramagnetic and a diamagnetic substance respectively. When a magnet is brought close to them, then it will ____________.
The magnetic property of magnetic substance is associated with ____________.
Above the curie temperature the susceptibility of ferromagnetic substance varies ____________.
The earth’s field departs from its dipole shape substantially at large distances (greater than about 30,000 km). What agencies may be responsible for this distortion?
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.
Which graph shows the variation of magnetic susceptibility (`chi`) with magnetizing field (H) for a paramagnetic substance?
Why does a paramagnetic sample display greater magnetisation (for the same magnetising field) when cooled?
Why is diamagnetism, in contrast, almost independent of temperature?
Would the maximum possible magnetisation of a paramagnetic sample be of the same order of magnitude as the magnetisation of a ferromagnet?
Explain qualitatively on the basis of domain picture the irreversibility in the magnetisation curve of a ferromagnet.
What kind of ferromagnetic material is used for coating magnetic tapes in a cassette player, or for building ‘memory stores’ in a modern computer?
Nickel shows ferromagnetic property at room temperature. If the temperature is increased beyond curie temperature, then it will show ______.
Assertion: A paramagnetic sample display greater magnetisation (for the same magnetic field) when cooled.
Reason: The magnetisation does not depend on temperature.
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
If a charged particle at rest experience no electromagnetic force
A permanent magnet in the shape of a thin cylinder of length 10 cm has M = 106 A/m. Calculate the magnetisation current IM.
An ammeter of resistance R gives a full-scale deflection when a current of 2 A passes through it. If it is measured with a maximum current of 10 A, the required shunt is ______.
- Assertion (A): Diamagnetic substances exhibit magnetism.
- Reason (R): Diamagnetic materials do not have a permanent magnetic dipole moment.
The relative magnetic permeability of a substance X is slightly less than unity and that of substance Y is slightly more than unity, then ______.
What is magnetic hysterisis?
Explain ferromagnetism on the basis of the domain theory.
State the dimensions of magnetization.
Magnetic susceptibility of a diamagnetic substance ______.
