The study was conducted to map the misconception pattern of chemistry prospective teachers who learned acid-base and argentometric titration. Further, it attempts to minimize misconception through a multiple representation model of learning chemistry with cognitive dissonance strategy. The first treatment was done on acid-base titration and the second treatment on argentometric titration materials. The multiple choice test with open reasons was administered to 30 undergraduate students. The finding shows that 28.6% students have the same pattern of misconception while learning in both of the courses. After the treatment, misconception decreased to 9.5% on the first treatment, and 9.4% on the second treatment. The model was found to be suitable to decrease the misconception, but could not change the misconception into "zero misconception", especially for microscopic and symbolic representations.

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We suggest a simple, practical device with a wireless sensor network system that can be used to record and display data from a spring oscillation system in real-time on a website. The HC-SR04 ultrasonic sensor was utilized to detect changes in load position in the damped spring oscillation system, and the Node-MCU ESP266 was used to transmit data from sensor readings to the server over the internet network. The damping factor, damping coefficient, and spring damping frequency could be utilized to calculate the exponential function graph fitting outcome.

This study proposes an online practicum model supported by Wireless Sensor Network (WSN) to implement a physics practicum after the Covid 19 Pandemic. This system is guided by exploratory inquiry questions to help structure students’ mindsets in answering investigative questions. Online practicum is also integrated with video conferencing, chat, evaluation system, and lab inquiry stages. The sensor measurement process is carried out directly via live streaming video, where the sensor measurement results are sent in real-time to the website via an internet connection. This study was conducted on 25 students (10 male and 15 female) who were prospective physics teachers. This study used a pre-experimental method with a one-group pretest and post-test design. The study results show that the online practicum model supported by WSN can effectively increase the inquiry skill of prospective physics teacher students. Usability test results obtained an average score of SUS 91.63, which means the practicum system can be categorized as having a user acceptance level of Excellent.

The problem frequently encountered in physics practicum activities is measuring instruments in limited reading data variable time of dynamic moving objects. In practical exercises needed the accuracy of measurement data to avoid a mistake in analysis and interpretation data. R-TDA of Dynamic Moving Objects measurement tool is expected to be a solution to overcome these problems. The electronic components used are Infra-Red Obstacle Sensor, connector cable, NodeMCU. The principle of this device is to send a recording time of modulo infrared to the cloud server and accessed via a smartphone and Personal Computer. The results show the sensor a responsive time of 6.8 x 10-11 seconds, and the effect of gravity acceleration of 9,70 m/s2 close to universal gravity acceleration 9,81 m/s2 with an average relative error of 1.22%. The R-TDA of Dynamic Moving Objects has a high response time and accuracy in recording the time of dynamic moving objects.