7. (a) Explain the working principle of a transformer and draw a sketch showing parts of a core type transformer. (b) What is MOSFET? With the help of a suitable diagram, explain the working of different MOSFET. 8. (a) Define Transducer. How are these classified? Give four examples of active transducers. (b) What is Zener Diode? Explain its use as voltage regulator. 9. (a) Discuss basic principle of operation for inductive transducers. Briefly explain working of LVDT. (b) What is JK flip-flop? Discuss its working. What is race around condition?