Home
Class 12
PHYSICS
An electron of charge e and mass m is mo...

An electron of charge e and mass m is moving in circular path of radius r with a uniform angular speed .` omega` Then which of the following statements are correct

A

The equivalent current flowing in the circular path is proportional to `r^(2)`

B

The magnetic moment due to circular current loop is independent of m

C

The magnetic moment due to circular current loop is equal to 2e/m time the angular momentum of the electron

D

The angular momentum of the particle is proportional to the areal velocity of electron

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question regarding the electron moving in a circular path, we will analyze each statement provided and determine their validity step by step. ### Step 1: Understanding the Motion of the Electron An electron of charge \( e \) and mass \( m \) is moving in a circular path of radius \( r \) with a uniform angular speed \( \omega \). The speed \( v \) of the electron can be expressed as: \[ v = r \cdot \omega \] This indicates that the electron is undergoing uniform circular motion. **Hint:** Remember that the relationship between linear speed and angular speed is given by \( v = r \cdot \omega \). ### Step 2: Finding the Equivalent Current The equivalent current \( I \) due to the moving charge can be calculated. The time period \( T \) for one complete revolution is: \[ T = \frac{2\pi r}{v} = \frac{2\pi r}{r \cdot \omega} = \frac{2\pi}{\omega} \] The current is given by: \[ I = \frac{Q}{T} = \frac{e}{T} = \frac{e \cdot \omega}{2\pi} \] This shows that the current is proportional to \( \omega \) and does not depend on \( r \). **Hint:** The current is calculated by dividing the charge by the time period for one complete revolution. ### Step 3: Analyzing the Statements 1. **Statement 1:** The equivalent current flowing in the circular path is proportional to \( r^2 \). - **Analysis:** We found that the current \( I \) is independent of \( r \). Hence, this statement is **incorrect**. 2. **Statement 2:** The magnetic moment due to a circular current loop is independent of mass \( m \). - **Magnetic Moment Calculation:** The magnetic moment \( \mu \) is given by: \[ \mu = I \cdot A = I \cdot \pi r^2 \] Substituting for \( I \): \[ \mu = \left(\frac{e \cdot \omega}{2\pi}\right) \cdot \pi r^2 = \frac{e \cdot \omega \cdot r^2}{2} \] This shows that the magnetic moment depends on \( r^2 \) and \( \omega \), but not on \( m \). Hence, this statement is **correct**. 3. **Statement 3:** The magnetic moment due to a circular current loop is equal to \( \frac{2e}{m} \) times the angular momentum of the electron. - **Angular Momentum Calculation:** The angular momentum \( L \) is given by: \[ L = m \cdot v \cdot r = m \cdot (r \cdot \omega) \cdot r = m \cdot r^2 \cdot \omega \] The relationship between magnetic moment and angular momentum is: \[ \mu = \frac{e}{2m} L \] This means that the magnetic moment is \( \frac{e}{2m} \) times the angular momentum, not \( \frac{2e}{m} \). Hence, this statement is **incorrect**. 4. **Statement 4:** The angular momentum of the electron is proportional to the aerial velocity of the electron. - **Aerial Velocity:** The aerial velocity is defined as the rate at which area is swept out by the radius vector. For uniform circular motion, this is constant and can be shown to be proportional to angular momentum. Thus, this statement is **correct**. ### Conclusion Based on the analysis: - **Correct Statements:** 2 and 4 - **Incorrect Statements:** 1 and 3 The final answer is that statements 2 and 4 are correct.

To solve the question regarding the electron moving in a circular path, we will analyze each statement provided and determine their validity step by step. ### Step 1: Understanding the Motion of the Electron An electron of charge \( e \) and mass \( m \) is moving in a circular path of radius \( r \) with a uniform angular speed \( \omega \). The speed \( v \) of the electron can be expressed as: \[ v = r \cdot \omega \] This indicates that the electron is undergoing uniform circular motion. ...
Promotional Banner

Topper's Solved these Questions

  • MAGNETIC EFFECTS OF CURRENT

    ERRORLESS|Exercise NCERT BASED QUESTIONS (Force and Torque on a Current Carrying Conductor )|51 Videos
  • MAGNETIC EFFECTS OF CURRENT

    ERRORLESS|Exercise PAST YEARS QUESTIONS |48 Videos
  • MAGNETIC EFFECTS OF CURRENT

    ERRORLESS|Exercise ASSERTION & REASON |18 Videos
  • ELECTROSTATICS

    ERRORLESS|Exercise ASSERTION & REASON|25 Videos
  • MAGNETISM

    ERRORLESS|Exercise Assertion and Reason|22 Videos

Similar Questions

Explore conceptually related problems

A particle of mass m is moving on a circular path of radius r with uniform speed v , rate of change of linear momentum is

A particle of mass 'm' is moving on a circular path of radius 'r' with uniform speed 'v'. Rate of change of linear momentum is

A particle of charge q and mass m moves in a circular orbit of radius r with angular speed omega . The ratio of the magnitude of its magnetic moment to that of its angular momentum depends on

A particle of the charged q and mass m moves in a circular orbit of radius r with angular speed omega . The ratio of the magnitude of its magnetic moment to that of its angular momentum depends on

A particle of charge q and mass m moves in a circular orbit or radius r with angular speed omega . The ratio of the magnitude of its magnetic moment to that of its angular momentum depends on

If a charged particle having charge q is moving in a circular path of radius R with a uniform speed u, what would be the magnetic field at the centre?

A particle is moving along a circular path. Which of the following statement is not correct?

A particle moving along a circule path of radius 'r' with uniform angular velocity omega . Its angular acceleration is

ERRORLESS-MAGNETIC EFFECTS OF CURRENT -NCERT BASED QUESTIONS (Motion of Charged Particle in Magnetic Field)
  1. The path executed by a charged particle whose motion is perpendicular ...

    Text Solution

    |

  2. A charged particle is released from rest in a region of steady and uni...

    Text Solution

    |

  3. A proton moving withh a velocity 2.5xx10^(7)m//s enters a magnetic fie...

    Text Solution

    |

  4. Motion of a moving electron is not affected by

    Text Solution

    |

  5. An electron enters into a region of uniform magnetic field of strength...

    Text Solution

    |

  6. When a charged particle moving with velocity vec(V) is subjected to a...

    Text Solution

    |

  7. An electron is projected with uniform velocity along the axis of a cur...

    Text Solution

    |

  8. A particle of mass 0.6g and having charge of 25 nC is moving horizonta...

    Text Solution

    |

  9. A horizontal rod of mass 10g and length 10cm is placed on a smooth pla...

    Text Solution

    |

  10. A long wire AB is placed on a table. Another wire PQ of mass 1.0 g and...

    Text Solution

    |

  11. The magnetic force acting on a charged particle of charge -2 muC in ...

    Text Solution

    |

  12. A metallic block carrying current I is subjected to a uniform magneti...

    Text Solution

    |

  13. A charged particle (charge q) is moving in a circle of radius R wit...

    Text Solution

    |

  14. An electron moves in a circular orbit with a uniform speed v.It produc...

    Text Solution

    |

  15. An electron of charge e and mass m is moving in circular path of radiu...

    Text Solution

    |

  16. A particle of charge q and mass m is moving along the x-axis with a ve...

    Text Solution

    |

  17. A wire carrying a current i is placed in a uniform magnetic field in t...

    Text Solution

    |

  18. A uniform magnetic field B and a uniform electric field E act in a com...

    Text Solution

    |

  19. A particle of mass 'm' and carrying a charge q enters with a velocity ...

    Text Solution

    |

  20. A thin ring of 10 cm radius carries a uniformly distributed charge. Th...

    Text Solution

    |