The technological, pedagogical and content knowledge (TPACK) framework was developed incorporating content, pedagogical and technological knowledge. Studies used TPACK constructs and reported on teachers' TPACK and student learning, but none explored the correlation between teachers' TPACK and the achievement of their learners. This research followed an exploratory correlational research design involving 1423 Grade 11 learners and their 42 Physics teachers in a South African district after electricity was taught. A self-report questionnaire may not truly measure teachers' TPACK, therefore, learners' perceptions of their teachers' use of technology were explored. The correlation between the Physics teachers' TPACK and the achievement of their learners in electricity was established. Four validated research instruments were used, namely, the Learner Electricity Achievement Test (LEAT), the Learner Confirmatory Questionnaire (LCQ), the Teachers' Technological, Pedagogical and Content Knowledge Questionnaire (T-TPACKQ) and the Learners' Confirmation of the Teachers' Technological, Pedagogical and Content Knowledge Questionnaire (LC-T-TPACKQ). Findings indicate a statistically significant difference between teachers' views of their TPACK and the views of their learners. The correlation between teachers' TPACK and the achievement of their learners was not statistically significant. These results can influence the professional development of teachers in respect of the use of technology in teaching.