Assertion (A): The optical dielectric constant (i.e., ?r at optical frequencies)

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Question
Assertion (A): The optical dielectric constant (i.e., ?_r at optical frequencies)of ionic dielectrics is less than static dielectric constant.
Reason (R): At optical frequencies, P_i = 0.
Options
A. Both A and R are true and R is correct explanation of A
B. Both A and R are true but R is not correct explanation of A
C. A is true but R is false
D. A is false but R is true

Correct Answer

Both A and R are true and R is correct explanation of A

More questions

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B. critical wavelength for TE₁₀ mode is one half of that for TE₁₀ mode
C. critical wavelength for TE₁₀ mode is the same as that for TM₁₀ mode
D. critical wavelength for TE₁₀ mode is double that for TE₀₁mode

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A. 3
B. 4
C. 5
D. 6

3. The first and second subscripts in models of circular waveguides depict
Options
A. the number of full sine wave variations in circumference in direction and Bessel function variations in radial direction respectively
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D. none of the above

4. Which of the following is not a travelling wave?
Options
A. e = E_m sin (?x - ?t)
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C. Class C
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Options
A. 24.09 MHz
B. 24.54 MHz
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8. A TR (transmitter receiver) tube has
Options
A. low loss for low power signals and high
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10. Assertion (A): If W_F is Fermi energy, v is velocity of electron and m is mass of electron, then .
Reason (R): Conductivity of a metal depends on temperature and impurity concentration.
Options
A. Both A and R are true and R is correct explanation of A
B. Both A and R are true but R is not correct explanation of A
C. A is true but R is false
D. A is false but R is true

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