DPS MEGACITY, KOLKATA Practice Worksheet CLASS IX PHYSICS 1. Why is rachet essential for screw gauge? 2. Define least count of an instrument. 3. The least count of a screw gauge is 0.02 mm. If the 47th division on circular scale coincides with the line of graduation of main scale, find the circular scale reading. 4. With the help of proper labelled diagram, explain how negative zero error of vernier constant is determined. 5. Calculate the length of second s pendulum on the surface of the moon, where acceleration due to gravity is 1/6th the acceleration due to gravity on earth. 6. What is backlash error? How can it be avoided? 7. Find the relation between the following: i) parsec and lightyear. ii) nanometer and angstrom. 8. Calculate the frequency of oscillations of a simple pendulum of length 0.60m. 9. Find the number of times the heart of a human beings beats in 10 years. Assume that the heart beats once in 0.8 s. 10. Explain how can you obtain the value of acceleration due to gravity from simple pendulum experiment. 11. A simple pendulum is taken to the poles and experiment is being performed to measure time period. Will the pendulum swing faster or slower? Justify your answer. 12. Draw the graph showing the variation of T2 with l. How will you use this graph to determine the value of g (acceleration due to gravity)? 13. The mass of an atom of Nitrogen is 14.0 u. Express it in kg.
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