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(A ): Speed of EM wave in a medium depen...

(A ): Speed of EM wave in a medium depends on electrical permittivity and magnetic permeability of the medium (R) E.M wave transport energy in the form of oscillating electric and magnetic fields

A

Both 'A' and 'R' are true and 'R' is the correct explanation of 'A'.

B

Both 'A' and ’R' are true and 'R' is not the correct explanation of 'A

C

A' is true and 'R' is false

D

'A' is false and R' is true

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The correct Answer is:
To solve the question regarding the properties of electromagnetic (EM) waves in a medium, we will analyze both statements provided: ### Step 1: Understanding the Speed of EM Waves in a Medium The speed of electromagnetic waves in a medium is determined by the electrical permittivity (ε) and magnetic permeability (μ) of that medium. The formula for the speed of EM waves (v) in a medium can be expressed as: \[ v = \frac{1}{\sqrt{\mu \cdot \epsilon}} \] Where: - \( \mu \) is the magnetic permeability of the medium. - \( \epsilon \) is the electrical permittivity of the medium. ### Step 2: Identifying the Components of Permittivity and Permeability In a medium, the electrical permittivity can be expressed as: \[ \epsilon = \epsilon_0 \cdot \epsilon_r \] And the magnetic permeability can be expressed as: \[ \mu = \mu_0 \cdot \mu_r \] Where: - \( \epsilon_0 \) and \( \mu_0 \) are the permittivity and permeability of free space (vacuum). - \( \epsilon_r \) and \( \mu_r \) are the relative permittivity and relative permeability of the medium. ### Step 3: Substituting into the Speed Formula Substituting the expressions for permittivity and permeability into the speed formula gives: \[ v = \frac{1}{\sqrt{\mu_0 \cdot \mu_r \cdot \epsilon_0 \cdot \epsilon_r}} \] This shows that the speed of EM waves in a medium depends on both the electrical permittivity and magnetic permeability of the medium. ### Step 4: Analyzing the Energy Transport Electromagnetic waves transport energy through oscillating electric and magnetic fields. This is a fundamental characteristic of EM waves, where the electric field (E) and magnetic field (B) oscillate perpendicular to each other and to the direction of wave propagation. This oscillation allows EM waves to carry energy through space. ### Step 5: Conclusion Based on the analysis: - Statement (A) is correct: The speed of EM waves in a medium does depend on the electrical permittivity and magnetic permeability of that medium. - Statement (R) is also correct: EM waves do transport energy in the form of oscillating electric and magnetic fields. Thus, both statements are true. ### Final Answer Both statements (A) and (R) are correct. ---
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AAKASH SERIES-ELECTROMAGNETIC WAVES-EXERCISE -IB
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  2. (A) : In Ampere Maxwell law, displacement current has same physical ef...

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  3. (A ): Speed of EM wave in a medium depends on electrical permittivity ...

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  4. (A ): E.M. waves can show diffraction effect (R) : E.M waves are trans...

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  5. (A ): In electromagnetic wave, electric and magnetic fields oscillate ...

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  6. (A ): The light can travel in vacuum but sound cannot do so (R) : Ligh...

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  7. (A): Gamma rays are more energetic than X-rays (R) : Gamma rays are of...

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  8. Assertion : The earth without its atmosphere would be inhospitably col...

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  9. A : Environmental damage has depleted the ozone layer in the atmosphe...

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  10. (A) : The microwaves are better carriers of signals than radio waves. ...

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  11. Assertion (A) : The presence of CO(2) in the air accelerates corrosio...

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  12. A satellite orbiting close to the surface of earth does not fall down ...

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  13. (A) : The average magnitude of poynting vector vecS is the intensity o...

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  14. A : Long distance radio broadcasts use short-wave bands. R : Ionosp...

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  15. A : It is necessary to use satellites for long distance TV transmissi...

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  16. A : Optical and radio telescopes are built on the ground but X-ray ...

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  17. The ozone layer on the top of the stratosphere is crucial for human su...

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  18. Assertion A pulsar is a source of radio waves that varies in intensity...

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  19. (A) : Quasar emits radiowaves more than radio galaxy. (R) : Quasar has...

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  20. (A) : Dipole oscillations produce electro­magnetic waves. (R) : Accel...

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