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Moving Charges and Magnetism

Moving Charges and Magnetism

Edited By Team Careers360 | Updated on May 06, 2022 09:42 AM IST

Introduction:
One of the most fundamental forces known is the magnetic pull on a moving charge. The electrostatic or Coulomb force is just as essential as the magnetic force. The magnetic force, on the other hand, is more complicated than the comparatively basic Coulomb force, both in terms of the number of things that impact it and in terms of its direction. The magnetic field is the area surrounding a magnet or a current-carrying conductor in which its magnetic effect may be felt. Tesla is the SI unit for it (T). In a magnetic field, the force exerted on a moving charge. The force felt by a unit charge moving with unit velocity perpendicular to the magnetic field direction is known as magnetic field strength. A cyclotron is a particle accelerator that accelerates charged particles outwards from its centre in a spiral route.

A static magnetic field keeps the particles on a spiral route, while a rapidly fluctuating electric field accelerates them. By coupling a stream of electrons with a magnetic field, the cavity magnetic coil is a high-powered vacuum tube that creates microwaves. Radar, warmth, and light are all possible uses for the magnetron.. The cross product of the magnetic moment and the field vector determines the torque experienced by a current-carrying coil in a magnetic field. As a result, the torque is greatest when the dipole moment is perpendicular to the field, and zero when it is parallel or antiparallel to the field. When the dipole moment is parallel to the field, the dipole is in stable equilibrium. When it's antiparallel, it's in an unstable equilibrium state.

List of topics according to NCERT and JEE Main/NEET syllabus:

  • force on a moving charge in a magnetic field

  • Magnetic field strength

  • S.I. unit of magnetic field intensity

  • Biot-Savart’s law

  • Applications of Biot-Savart’s law:

  • Ampere’s circuital law:

  • Application of Ampere’s circuital law:

  • Motion in a uniform electric field of a charged particle

  • Force on a moving charge in uniform magnetic and electric field or motion in combined electric and magnetic field

  • cyclotron motion in a magnetic field

  • Force acting on a current carrying conductor kept in a magnetic field

  • The force between two parallel current-carrying conductors

  • Torque experienced on a current carrying coil kept in a magnetic field

  • Moving coil galvanometer

Related Topics,

Important concepts and Laws of moving charges and magnetism ncert:

force on a moving charge in a magnetic field - Moving charges are subjected to a magnetic field. The force exerted on a moving charge stays perpendicular to the plane produced, which is indicated by 'v' and 'B', respectively. In this scenario, the 'Right-Hand Rule' is applied. Furthermore, the amount of the force is proportional to the sine of the angle formed by 'B' and 'v'.

Biot-Savart’s law - Current sources and magnetic fields are involved in the legislation. The magnetic field is determined by the current distribution, which involves vector products. It contains a calculus problem in which the distance between field points and current is continually changing. Calculating the magnetic influence on a molecular and atomic level, as well as measuring velocity in aerodynamics, are two of its main applications.

Ampere’s circuital law - The connection between the magnetic field and its source current is described by Ampere's Circuital Law. The product of current in the medium and permeability of the latter equals the magnetic field density on an imagined enclosed channel.

The torque experienced by a current-carrying coil in a magnetic field is the cross product of the magnetic moment and the field vector. As a result, when the dipole moment is perpendicular to the field, the torque is highest, and when it is parallel or antiparallel to the field, the torque is zero. The dipole is in stable equilibrium when the dipole moment is parallel to the field. It's in an unstable equilibrium condition when it's antiparallel.

NCERT Notes Subject wise link:

Importance of moving charges and magnetism class 12

For more than a century, magnetism and moving charges, i.e. electricity, have been explored. The phenomenon seen with the alignment of a needle was the forerunner to the connection between the two. It was discovered that its alignment is tangent to an imagined circle with a straight wire in the centre and a plane perpendicular to the wire. When current is passed, however, the needle's orientation shifts. The production of a magnetic field is thought to be caused by the passage of charges. moving charges and magnetism class 12 is an important topic in the board test, as well as a critical component of the joint entrance exam (jee) and the National Eligibility Entrance Test (neet ). Students must be thorough in their studies in order to do well in the category 12 board exam. In order to acquire outstanding scores in class 12, students must prepare properly and practise with ncert solutions for class 12 physics moving charges and magnetism physics.

NCERT Solutions Subject wise link:

NCERT Exemplar Solutions Subject wise link:

Frequently Asked Question (FAQs)

1. ​​What Are Ampere's Circuital Law's Different Applications?

Moving charges and magnetism class 12 Physics a comprehensive description of the different uses of Ampere's Circuital Law is included in  ncert solutions for class 12 physics moving charges and magnetism

(1) long current-carrying wire produced magnetism

(2) long current-transmitting cylinder generating a magnetic field,

(3) current-carrying hollow cylinders creating a magnetic field are all examples. 

2. How do moving charges and magnetism relate to each other?

Magnetism is caused by moving charges or charge flow. Magnetic fields also impose forces on the flow of charge, which in turn exerts forces on other magnets, according to ncert solutions for class 12 physics moving charges and magnetism. Because of the existence of continuous moving charges, such a phenomenon occurs.

3. What are the Biot Savart Law's Applications?

The Biot Savart Law is discussed in class 12  Moving Charges and Magnetism. The law's main applications are:

 (1) calculating magnetic responses at the atomic and molecular level

(2) determining velocity in aerodynamics theory.

4. What Does a Cyclotron Understand?

The cyclotron is one of the first particle accelerators, as explained in class 12  Moving Charges and Magnetism. Prototypes are still used in the earliest stages of specialised multi-stage particle accelerators, despite having undergone a slew of changes since then. The attribute of a magnetic force's influence on a moving charge is also used to bend the latter along a semi-circular trajectory

5. What proportion of questions on moving charges and magnetism are asked in the board exam?

There is variety because of the different patterns, thus roughly 10 to 15 percent of questions concerning moving charges and magnetism are asked.

6. In NEET, on average, how many questions related to moving charges and magnetism are asked?

In the NEET examination, an average of one question is asked, with a weightage from around two per cent on moving charges and magnetism

Articles

Get answers from students and experts

 5 g of Na2SO4 was dissolved in x g of H2O. The change in freezing point was found to be 3.820C.  If Na2SO4 is 81.5% ionised, the value of x (Kf for water=1.860C kg mol−1) is approximately : (molar mass of S=32 g mol−1 and that of Na=23 g mol−1)
Option: 1  15 g
Option: 2  25 g
Option: 3  45 g
Option: 4  65 g  
 

 50 mL of 0.2 M ammonia solution is treated with 25 mL of 0.2 M HCl.  If pKb of ammonia solution is 4.75, the pH of the mixture will be :
Option: 1 3.75
Option: 2 4.75
Option: 3 8.25
Option: 4 9.25
 

CH_3-CH=CH-CH_3+Br_2\overset{CCl_4}{\rightarrow}A

What is A?

Option: 1

CH_3-CH(Br)-CH_2-CH_3


Option: 2

CH_3-CH(Br)-CH(Br)-CH_3


Option: 3

CH_3-CH_2-CH_2-CH_2Br


Option: 4

None


\mathrm{NaNO_{3}} when heated gives a white solid A and two gases B and C. B and C are two important atmospheric gases. What is A, B and C ?

Option: 1

\mathrm{A}: \mathrm{NaNO}_2 \mathrm{~B}: \mathrm{O}_2 \mathrm{C}: \mathrm{N}_2


Option: 2

A: \mathrm{Na}_2 \mathrm{OB}: \mathrm{O}_2 \mathrm{C}: \mathrm{N}_2


Option: 3

A: \mathrm{NaNO}_2 \mathrm{~B}: \mathrm{O}_2 \mathrm{C}: \mathrm{Cl}_2


Option: 4

\mathrm{A}: \mathrm{Na}_2 \mathrm{OB}: \mathrm{O}_2 \mathrm{C}: \mathrm{Cl}_2


C_1+2 C_2+3 C_3+\ldots .n C_n=

Option: 1

2^n


Option: 2

\text { n. } 2^n


Option: 3

\text { n. } 2^{n-1}


Option: 4

n \cdot 2^{n+1}


 

A capacitor is made of two square plates each of side 'a' making a very small angle \alpha between them, as shown in the figure. The capacitance will be close to : 
Option: 1 \frac{\epsilon _{0}a^{2}}{d}\left ( 1 - \frac{\alpha a }{4 d } \right )

Option: 2 \frac{\epsilon _{0}a^{2}}{d}\left ( 1 + \frac{\alpha a }{4 d } \right )

Option: 3 \frac{\epsilon _{0}a^{2}}{d}\left ( 1 - \frac{\alpha a }{2 d } \right )

Option: 4 \frac{\epsilon _{0}a^{2}}{d}\left ( 1 - \frac{3 \alpha a }{2 d } \right )
 

 Among the following compounds, the increasing order of their basic strength is
Option: 1  (I) < (II) < (IV) < (III)
Option: 2  (I) < (II) < (III) < (IV)
Option: 3  (II) < (I) < (IV) < (III)
Option: 4  (II) < (I) < (III) < (IV)
 

 An ideal gas undergoes a quasi static, reversible process in which its molar heat capacity C remains constant.  If during  this process the relation of pressure P and volume V is given by PVn=constant,  then n is given by (Here CP and CV are molar specific heat at constant pressure and constant volume, respectively)
Option: 1  n=\frac{C_{p}}{C_{v}}


Option: 2  n=\frac{C-C_{p}}{C-C_{v}}


Option: 3 n=\frac{C_{p}-C}{C-C_{v}}

Option: 4  n=\frac{C-C_{v}}{C-C_{p}}
 

As shown in the figure, a battery of emf \epsilon is connected to an inductor L and resistance R in series. The switch is closed at t = 0. The total charge that flows from the battery, between t = 0 and t = tc (tc is the time constant of the circuit ) is : 


Option: 1 \frac{\epsilon L }{R^{2}} \left ( 1 - \frac{1}{e} \right )
Option: 2 \frac{\epsilon L }{R^{2}}


Option: 3 \frac{\epsilon R }{eL^{2}}

Option: 4 \frac{\epsilon L }{eR^{2}}
 

As shown in the figure, a particle of mass 10 kg is placed at a point A. When the particle is slightly displaced to its right, it starts moving and reaches the point B. The speed  of the particle at B is x m/s. (Take g = 10 m/s2 ) The value of 'x' to the nearest is ___________.
Option: 1 10
Option: 2 20
Option: 3 40
Option: 4 15

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