Bissoy.com
Doctors Medicines MCQs Q&A

What is the physical significance of the negative sign for the refractive indices of metamaterials?

What is the physical significance of the negative sign for the refractive indices of metamaterials? Correct Answer Antiparallel phase velocity of a wave

Negative index metamaterials have negative refractive index by virtue of the simultaneous negative permittivity and negative permeability. This negative sign is consistent with the laws of physics and has a physical significance indicating that the phase velocity of a wave is antiparallel to its group velocity.

Related Questions

A crown glass prism with refractive index 6° is to be achromatized for red and blue color light with flint glass prism. What will be the angle of flint glass prism? (µr = 1.513, µr‘ = 1.645, µ2 = 1.523 and µ2‘ = 1.665, Where µr and µ2 are refractive indices of red and blue light respectively whereas, µr‘ and µ2‘ are refractive indices of red and blue light respectively for flint glass.)
Choose the correct relation for a combination of two prisms to be achromatic. (Where for the first prism: μv = refractive index of the medium in violet light, μr = refractive index of the medium in red light A = angle of the prism; For the second prism: μ′v = refractive index of the medium in violet light, μ′r = refractive index of the medium in red light, A’ = angle of prism.)
Match the items of List - II with the items of List - I and select the code of correct matching List - I List - II (a) Chi-square Test (i) Testing the significance of the differences of the mean values among more than two sample groups. (b) ANOVA (F-test) (ii) Testing the goodness of fit of a distribution (c) Z - test (iii) Testing the significance of the difference of the mean values between two large sized samples (d) t - test (iv) Testing the significance of the difference of the mean values between two small sized samples when population standard deviation is not available  
Which of the following statements are correct
1. Significance level is opposite to confidence level.
2. Significance level is complementary to confidence level.
3. Significance level is the rejection area.
Crisil Research launched benchmark indices for the industry. How many indices will be covered under AIF categories?
Consider the following consume price indices. I. Consumer Price Index for Industrial Workers II. Consumer Price Index for Agricultural Labourers III. Consumer Price Index for Rural Labourers IV. Consumer Price Index for Urban Non-Manual Employees   Which of the above indices is/are compiled by Central Statistical Organization (CSO)?
Noise levels at a traffic site are recorded for one hour at a sampling interval of 1 second and percentile indices of noise L1, L10, L50, L90 are computed from the data. The indices are then arranged in increasing order in terms of their values starting from minimum to maximum. which of the following options represents their correct order?
Indices whose search key specifies an order different from the sequential order of the file are called ___________ indices.
State true or false: Clustering indices are also called as primary indices
Miller indices of any crystallographic plane are specified with three indices. A crystallographic plane is defined in terms of the length of its intercepts on three axes, measured from the origin of the coordinate axes.