Due to the outbreak of Covid-19 pandemic, most schools in Mizoram shifted to online learning platforms to continue with their academic activities. A survey was carried out using a questionnaire to identify the effectiveness of online learning. 356 students and 60 teachers from different secondary and higher secondary schools in Mizoram responded to this survey. To find the effectiveness of online learning, percentages were calculated to analyze the data and the mathematical consensus (Cns) were calculated. Students’ preferences and perceptions on various attributes of online classes were analyzed. The results indicated that most of the students and teachers were not quite ready to shift to online learning platforms. Bad internet connectivity, low data limits, slow data speed, demand for costly devices such as smart phones and related software and connectivity were problems faced in conducting online classes. It was found that the students preferred using smart phones to follow online classes, and mathematics was the most difficult subject to learn or teach in online classes.

The problem of the symmetric and antisymmetric vibrations are attempted for the elastic plate with voids immersed in a liquid. The frequency equations are derived and deduced for the cases of plate wave, flexural and Rayleigh waves. It is also derived the cases when the liquid is replaced by vacuum/air. The two modes of vibration for the modified symmetric, antisymmetric, plate, flexural and Rayleigh waves in the considered medium are discussed. Numerically and analytically, the phase speeds and attenuations of symmetric and antisymmetric vibration, plate wave, flexural and Rayleigh waves are computed for a particular model. The effects of voids parameters on the phase speeds are also discussed.

The effect of mechanical relaxation time in the elastic wave propagation in elastic materials with voids is investigated. The phase speed and the attenuation coefficients are obtained and observed the effect of mechanical relaxation time. The phenomenon of reflection of elastic waves due to the incident waves from a plane boundary of elastic materials with voids is studied. The amplitude and energy ratios of the reflected waves are obtained. Numerically these ratios, phase speeds and the corresponding attenuation coefficients are computed for a particular model and the effect of mechanical relaxation time is discussed.

The geography of the Mizoram state makes it a remote state. Due to its remoteness, connectivity and modern ICT application in teaching and learning remain a vital concern in the state. Therefore, it is an immediate need to know how teachers use information and communication technologies (ICT) in mathematics teaching. To understand how teachers use ICT, an investigation of the various factors that may impact ICT use in content areas such as mathematics is the need of the hour. This study investigates the availability and frequency of ICT use and examines factors contributing to the barrier to teachers ICT use in mathematics teaching. This analysis showed that ICT resources are available to all the teachers in the region, the lack of interest in teaching in ICT is depends on the teachers experience, the type of school does not determine the ICT implementation, whether it is government or private and ICT training programmes conducted by the government does not reach to all the teachers in the state. The finding can provide vital links to help stakeholders and the government for effective use of ICT in mathematics teaching.