ncert sound class 9 .What are activity 12.1 and 12.2 observations?(pg no 160) Share with your friends Share 0 Shivam Menroy answered this Kya -2 View Full Answer Sanskriti Srivastava answered this For activity 12.1 You can find your answer the given image 1 Sanskriti Srivastava answered this For activity 2 You can find your answer the given image 3 Khushal Shakya answered this I know about the ultrasonic sound -1 Amit Madake answered this Activity 12.1 and 12.2 sound 0