Home
Class 12
PHYSICS
A plane electromagnetic wave travels in ...

A plane electromagnetic wave travels in vacuum along z- direction. What can you say about the directions of its electric and magnetic field vectors? If the frequency of the wave is 30 MHz, what is its wavelength?

Text Solution

Verified by Experts

In this case, the electric field `vecE` and magnetic field `vecB` are perpendicular to each other and lie on the xy-plane.
`because c=flambda`
`therefore lambda=c/f=(3xx10^8)/(30xx10^6)`=10 m
Promotional Banner

Topper's Solved these Questions

  • ELECTROMAGNETIC WAVES

    CHHAYA PUBLICATION|Exercise NCERT EXEMPLAR QUESTIONS|7 Videos

  • ELECTROMAGNETIC WAVES

    CHHAYA PUBLICATION|Exercise EXERCISE (MCQ)|18 Videos

  • ELECTROMAGNETIC WAVES

    CHHAYA PUBLICATION|Exercise HOTS QUESTIONS|5 Videos

  • ELECTROMAGNETIC INDUCTION & ALTERNATING CURRENT

    CHHAYA PUBLICATION|Exercise CBSE SCANNER|28 Videos

  • ELECTROMAGNETISM

    CHHAYA PUBLICATION|Exercise CBSE SCANNER|26 Videos

Similar Questions

Explore conceptually related problems

Some equipotential lines are shown in figure. What can you say about the magnitude and the direction of the electric field ?

A plane electromagnetic wave propagating along x-direction can have the following pairs of vecE and vecB

What are the directions of electric and magnetic field vectors relative to each other and relative to the direction of propagation of electromagnetic waves?

A point is in the XZ plane what can you say about its y coordinate

Electromagnetic waves propagate through free space or a medium as transverse waves. The electric and magnetic fields are perpendicular to each other as well as perpendicular to the direction of propagation of waves at each point. In the direction of wave propagation, electric field vecE and magnetic field vecB form a right-handed cartesian coordinate system. During the propagation of electromagnetic wave, total energy of electromagnetic wave is distributed equally between electric and magnetic fields. Since in_0 and mu_0 are permittivity and permeability of free space, the velocity of electromagnetic wave, c=(in_0 mu_0)^(-1//2) . Energy density i.e., energy in unit volume due to electric field at any point, u_E=1/2in_0E^2 Similarly, energy density due to magnetic field , u_M=1/(2mu_0)B^2 . If the electromagnetic wave propagates along x-direction, then the equations of electric and magnetic field are respectively. E=E_0sin(omegat-kx) and B=B_0sin(omegat-kx) Here, the frequency and the wavelength of oscillating electric and magnetic fields are f=omega/(2pi) and lambda=(2pi)/k respectively. Thus E_"rms"=E_0/sqrt2 and B_"rms"=B_0/sqrt2 , where E_0/B_0=c . Therefore, average energy density baru_E=1/2in_0E_"rms"^2 and baru_M=1/(2mu_0)B_"rms"^2 . The intensity of the electromagnetic wave at a point, I=cbaru=c(baru_E+baru_B) . To answer the following questions , we assume that in case of propagation of electromagnetic wave through free space, c=3xx10^8 m.s^(-1) and mu_0=4pixx10^(-7) H.m^(-1) If the peak value of electric field at a point in electromagnetic wave is 15 V . m^(-1) , then average electrical energy density (in j . m^(-3) )

Electromagnetic waves propagate through free space or a medium as transverse waves. The electric and magnetic fields are perpendicular to each other as well as perpendicular to the direction of propagation of waves at each point. In the direction of wave propagation, electric field vecE and magnetic field vecB form a right-handed cartesian coordinate system. During the propagation of electromagnetic wave, total energy of electromagnetic wave is distributed equally between electric and magnetic fields. Since in_0 and mu_0 are permittivity and permeability of free space, the velocity of electromagnetic wave, c=(in_0 mu_0)^(-1//2) . Energy density i.e., energy in unit volume due to electric field at any point, u_E=1/2in_0E^2 Similarly, energy density due to magnetic field , u_M=1/(2mu_0)B^2 . If the electromagnetic wave propagates along x-direction, then the equations of electric and magnetic field are respectively. E=E_0sin(omegat-kx) and B=B_0sin(omegat-kx) Here, the frequency and the wavelength of oscillating electric and magnetic fields are f=omega/(2pi) and lambda=(2pi)/k respectively. Thus E_"rms"=E_0/sqrt2 and B_"rms"=B_0/sqrt2 , where E_0/B_0=c . Therefore, average energy density baru_E=1/2in_0E_"rms"^2 and baru_M=1/(2mu_0)B_"rms"^2 . The intensity of the electromagnetic wave at a point, I=cbaru=c(baru_E+baru_B) . To answer the following questions , we assume that in case of propagation of electromagnetic wave through free space, c=3xx10^8 m.s^(-1) and mu_0=4pixx10^(-7) H.m^(-1) if the wavelength is 1000Å, then the frequency (in Hz)

CHHAYA PUBLICATION-ELECTROMAGNETIC WAVES -NCERT TEXTBOOK QUESTIONS
  1. A capacitor is made of two circular plates each of radius 12 cm, and s...

    Text Solution

    |

  2. Which physical quantity is the same for X-rays of wavelength 10^(-10) ...

    Text Solution

    |

  3. A plane electromagnetic wave travels in vacuum along z- direction. Wha...

    Text Solution

    |

  4. A charged particle oscillates about its mean equilibrium position with...

    Text Solution

    |

  5. In a plane electromagnetic wave, the electric field oscillates sinusoi...

    Text Solution

    |

  6. In a plane electromagnetic wave, the electric field oscillates sinusoi...

    Text Solution

    |

  7. In a plane electromagnetic wave, the electric field oscillates sinusoi...

    Text Solution

    |

  8. Suppose that the electric field part of an electromagnetic wave in vac...

    Text Solution

    |

  9. Suppose that the electric field part of an electromagnetic wave in vac...

    Text Solution

    |

  10. Suppose that the electric field part of an electromagnetic wave in vac...

    Text Solution

    |

  11. Suppose that the electric field part of an electromagnetic wave in vac...

    Text Solution

    |

  12. Suppose that the electric field part of an electromagnetic wave in vac...

    Text Solution

    |

  13. Given below are some famous numbers associated with electromagnetic ra...

    Text Solution

    |

  14. Given below are some famous numbers associated with electromagnetic ra...

    Text Solution

    |

  15. Given below are some famous numbers associated with electromagnetic ra...

    Text Solution

    |

  16. Given below are some famous numbers associated with electromagnetic ra...

    Text Solution

    |

  17. Why long distance radio broadcasts use short wave bands?

    Text Solution

    |

  18. Why use of satellites is necessary for long distance TV transmission?

    Text Solution

    |

  19. Optical and radio telescopes are built on ground but X-rays astronomy ...

    Text Solution

    |

  20. The small ozone layer on top of the stratosphere is crucial for human ...

    Text Solution

    |