Tag: neutral points

Questions Related to neutral points

A device used by the sailors to find the direction in which their ship is moving is called .................

properties of magnet magnetism physics neutral points magnetic poles and magnetic compass magnetic field

  1. horse shoe

  2. curve

  3. magnetic field

  4. magnetic needle

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Correct Option: D
Explanation:

A device used by the sailors to find the direction in which their ship is moving is called magnetic needle.
A compass contains a magnetic needle pivoted in a horizontal plane that indicates the direction of magnetic north at points on the earth's surface. It is an instrument containing a freely suspended magnetic element which displays the direction of the horizontal component of the Earth's magnetic field at the point of observation.
It is the oldest instrument for navigation and has been a vital tool for navigators at sea for centuries.

State whether true or false:

A tracing needle is used by the sailor for navigation.  

properties of magnet magnetism physics neutral points magnetic poles and magnetic compass magnetic field

  1. True

  2. False

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Correct Option: B
Explanation:

Magnetic compass is used for navigation while tracing needle is used for tracing magnetic field lines. 

The presence of magnetic field at a point can be detected by

properties of magnet magnetism physics neutral points magnetic poles and magnetic compass magnetic field

  1. ammeter 

  2. galvanometer

  3. a compass needle

  4. strong magnet

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Correct Option: C
Explanation:

A compass can be used to detect presence of magnetic field as it will deflect from its N-S direction to direction if magnetic field at that point.

The magnetic compass is not useful for navigation near the magnetic poles, since

properties of magnet magnetism physics neutral points magnetic poles and magnetic compass magnetic field

  1. $R=0$

  2. $V=0$

  3. $H=0$

  4. $\theta={0}^{o}$

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Correct Option: C
Explanation:

Near magnetic poles, $H=0$, therefore, magnetic compass will not work.

Two parallel conductors are separated by 5cm. They carry 6A and 2A in the same direction. Between them the location from first at which magnetic needle lies along $B _H$ is

properties of magnet magnetism physics neutral points magnetic poles and magnetic compass magnetic field

  1. 1.25 cm

  2. 3.75 cm

  3. 2.5 cm

  4. no point exist

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Correct Option: B

A magnetic needle oscillates in a horizontal plane with a period $T$ at a place where the angle of dip is $60^0$. When the same needle is made to oscillate in a vertical plane coinciding with the magnetic meridian, its period will be 

properties of magnet magnetism physics neutral points magnetic poles and magnetic compass magnetic field

  1. $\frac{T}{\sqrt 2}$

  2. T

  3. 2T

  4. 6T

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Correct Option: A

When a current of $1$ ampere is passed in a coil lying in the magnetic meridian then a magnetic needle at its centre gives some deflection. If the current in the coil is increased to $\sqrt8$ ampere then at what distance from the centre of the coil will the deflection of needle remains underchanged?

properties of magnet magnetism physics neutral points magnetic poles and magnetic compass magnetic field

  1. $2R$

  2. $4R$

  3. $8R$

  4. $R$

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Correct Option: B

The magnetic fields of atoms in a material are grouped together and aligned to form _________.

properties of magnet magnetic field moving charges and magnetism magnetic effects of current and magnetism physics neutral points magnetic poles and magnetic compass

  1. Strong magnetic fields

  2. An area of magnetic field

  3. A region called magnetic domain

  4. A bar magnet

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Correct Option: C
Explanation:

A magnetic domain is a region within a magnetic material in which the magnetization is in a uniform direction. This means that the individual magnetic moments of the atoms are aligned with one another and they point in the same direction.

The magnetic fields of atoms in a material are grouped together and aligned to form  region called magnetic domain

The smallest magnet available is ___________.

properties of magnet magnetic field moving charges and magnetism magnetic effects of current and magnetism physics neutral points magnetic poles and magnetic compass

  1. a bar magnet with an area of $1 mm^2$

  2. a spinning electron

  3. a magnetic dipole

  4. a molecule or atom with a magnetic dipole

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Correct Option: B
Explanation:

An electron is not a spinning ball of charge and the intrinsic spin of particles cannot be understood in such terms. a value of the ratio between the magnetic moment and the angular momentum that is a factor 2 too small.

The smallest magnet available is a spining electron.

The magnetic domains of an unmagnetised object are found ___________.

properties of magnet magnetic field moving charges and magnetism magnetic effects of current and magnetism physics neutral points magnetic poles and magnetic compass

  1. Parallel to each other

  2. Perpendicular to each other

  3. Pointing towards south

  4. Pointing in different direction

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Correct Option: D
Explanation:

A magnetic domain is the region in which the magnetic fields of atoms are grouped together and aligned. In an unmagnetized object the magnetic domains are pointing at different directions.