Transformational leadership (employee rated) was measured with the 7-item scale developed by Carless et al. (2000). An example item is “My leader communicates a clear and positive vision of the future.”
Carless, S. A., Wearing, A. J., & Mann, L. (2000). A short scale for measuring transformational leadership. Journal of Business and Psychology, 14(3), 389–406. https://doi.org/10.1023/A:1022991115523
MLQ (Multi-leadership questionnaire) by Avolio and Bass will contain questions relating to Transformational Leadership. It has 4 Likert-scale items under each dimension of Transformational Leadership