Q. No.2: Answer the following questions. i. Define physics.ii. Define optics.iii. What do you know about physical quantities?iv. Write base units.v. What are prefixes?vi. What is least count of Vernier callipers?vii. Define nuclear physicsviii. What is random motion?ix. Define displacement.x. What is uniform speed?xi. What is heat energy?xii. What do you know about efficiency of… Continue reading Previous paper class 9th(Physics)