A bar of magnetic substance is placed in a magnetic field with its length making an angle of $30^{\circ}$ with the direction of the magnetic field. How will the bar behave?
- It will align itself perpendicular to the magnetic field
- It will remain as before
- It will align itself parallel to the magnetic field
- Its behaviour cannot be predicted
The Correct Option is A
Solution and Explanation
Top Questions on Magnetic Field
- Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A : The potential (V) at any axial point, at 2 m distance(r) from the centre of the dipole of dipole moment vector \(\vec{P}\) of magnitude, 4 × 10-6 C m, is ± 9 × 103 V.
(Take \(\frac{1}{4\pi\epsilon_0}=9\times10^9\) SI units)
Reason R : \(V=±\frac{2P}{4\pi \epsilon_0r^2}\), where r is the distance of any axial point, situated at 2 m from the centre of the dipole.
In the light of the above statements, choose the correct answer from the options given below :- NEET (UG) - 2024
- Physics
- Magnetic Field
- In a uniform magnetic field of \(0.049 T\), a magnetic needle performs \(20\) complete oscillations in \(5\) seconds as shown. The moment of inertia of the needle is \(9.8 \times 10 kg m^2\). If the magnitude of magnetic moment of the needle is \(x \times 10^{-5} Am^2\); then the value of '\(x\)' is
- NEET (UG) - 2024
- Physics
- Magnetic Field
- A tightly wound \(100\) turns coil of radius \(10 cm\) carries a current of \( 7 A\). The magnitude of the magnetic field at the centre of the coil is (Take permeability of free space as \(4\pi×10^{-7}\) SI units):
- NEET (UG) - 2024
- Physics
- Magnetic Field
- An iron bar of length L has magnetic moment M. It is bent at the middle of its length such that the two arms make an angle 60° with each other. The magnetic moment of this new magnet is :
- NEET (UG) - 2024
- Physics
- Magnetic Field
- A sheet is placed on a horizontal surface in front of a strong magnetic pole. A force is needed to :
A. hold the sheet there if it is magnetic.
B. hold the sheet there if it is non-magnetic.
C. move the sheet away from the pole with uniform velocity if it is conducting.
D. move the sheet away from the pole with uniform velocity if it is both, non-conducting and non-polar.
Choose the correct statement(s) from the options given below :- NEET (UG) - 2024
- Physics
- Magnetic Field
Questions Asked in AIIMS exam
Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R
Assertion (A) : 02 is liberated in the non-cyclic photophosphorylation.
Reason (R) : Liberation of oxygen is due to photolysis of water.
In the light of the above statements, choose the correct answer from the options given below
- AIIMS - 2019
- Photosynthesis in higher plants
- Match the following column I with column II.
- AIIMS - 2019
- cloning
Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R
Assertion (A) : The Cro-Magnon man was the direct ancestor of the living modern man.
Reason (R) : Cro-Magnon man had slightly prognathous face.
In the light of the above statements, choose the correct answer from the options given below
- AIIMS - 2019
- evolution
- Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R
Assertion: Orbit of a satellite is within the gravitational field of earth whereas escaping is beyond the gravitational field of earth.
Reason: Orbital velocity of a satellite is greater than its escape velocity.
In the light of the above statements, choose the correct answer from the options given below- AIIMS - 2019
- Gravitation
Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R
Assertion (A) : In eukaryotes, transcription occurs in nucleus.
Reason (R) : In bacteria, transcription and translation occurs in cytoplasm.
In the light of the above statements, choose the correct answer from the options given below
- AIIMS - 2019
- Transcription
Concepts Used:
Magnetic Field
The magnetic field is a field created by moving electric charges. It is a force field that exerts a force on materials such as iron when they are placed in its vicinity. Magnetic fields do not require a medium to propagate; they can even propagate in a vacuum. Magnetic field also referred to as a vector field, describes the magnetic influence on moving electric charges, magnetic materials, and electric currents.
A magnetic field can be presented in two ways.
- Magnetic Field Vector: The magnetic field is described mathematically as a vector field. This vector field can be plotted directly as a set of many vectors drawn on a grid. Each vector points in the direction that a compass would point and has length dependent on the strength of the magnetic force.
- Magnetic Field Lines: An alternative way to represent the information contained within a vector field is with the use of field lines. Here we dispense with the grid pattern and connect the vectors with smooth lines.
Properties of Magnetic Field Lines
- Magnetic field lines never cross each other
- The density of the field lines indicates the strength of the field
- Magnetic field lines always make closed-loops
- Magnetic field lines always emerge or start from the north pole and terminate at the south pole.