This book introduces the teacher to the main principles and practices of the revised pedagogy which is activity-based, process oriented and learner-centred. The realisation that learning is not mere storing information in memory and that really earning is construction of knowledge through observation, comparison, classification and analysis has led us to give a new thrust to the teaching-learning process at Vocational Higher Secondary level to make it more meaningful and learner-friendly. This sourcebook has been developed primarily for the benefit of teachers who teach Maintenance and Repairs of Radio and Television at Vocational Higher Secondary level. The subject matter has been dealt with utmost care, in tune with the revised curriculum and pedagogic principles. It is hoped that this book will enable the teacher to provide suitable learning activities for effective learning. The success of the approach depends upon the vision and commitment of the teacher. They are expected to make use of this sourcebook at all stages of their teaching process. It is also expected that the teacher would seek help and guidance from other sources like libraries and websites. Hope that this courcebook will help the teacher to develop the skills and experience required for effective classroom transaction.