question: The COVID-19 pandemic has resulted in a physical shutdown of all types of educational institutes worldwide due to which the education delivery has now shifted to an "online only" exclusivity model. In this perspective, perceived usability of the online learning platforms that are currently being used is an important aspect, especially due to the absence of any physical classes. In this work Microsoft Teams is used as the reference platform for which the perceived usability is evaluated. For the evaluation purpose a dual strategy is followed by using the System Usability Scale (SUS), which is a Human Computer Interaction (HCI) based approach, and a modified Technology Acceptance Model (TAM), which is an Information Systems (IS) based approach. Although both these instruments are popular in their respective domains, yet they have not been considered simultaneously in one work for the purpose of usability evaluation. By doing so, this work attempts to streamline and unify the process of usability evaluation. Results that are obtained from a large-scale survey of university students show the similarity and equivalency between the two methodologies, with the Perceived Ease of Use (PEOU) construct of TAM having greater similarity with SUS. Moreover, this work also considers the digital-divide aspect (mobile vs. web environment) that is prevalent particularly in developing countries like India, and whether it has any effect on the perceived usability. Results show that the consumption platform does not have any effect on the usability aspect.