Virtual experiments are beneficial and effective learning activities providing the opportunity to investigate the relationship between the experimental findings and the theories. There exist several advantages of using virtual experiments, including, among other things: 7/24 availability, opportunity of unlimited iterations, and working with an experimental setup that seems to be impossible to construct in real settings. Yet, there are some limitations related to virtual experiments reported in the literature as well. The most prominent one of these limitations is the issues about their credibility. Thus, as researchers in physics education, we need to design more effective virtual experiments by eliminating or at least minimizing their drawbacks. Considered from this angle, in this experimental study, we aim to compare two kinds of virtual experiments designed using either photographic or graphic images to investigate the factors affecting the resistance of a conductor. These virtual experiments were experienced by 211 undergraduate students studying at the departments of primary education and science education. The findings show that the participants find the photographic version of the virtual experiment significantly more credible and they favor it more compared to the graphic version in affective dimension regardless of their gender, department, and the implementation order of the experiments.