# 1.Measurement

1. The diagram shows a micrometer scale. 2. Which quantity does not have a unit?

3. The diagram shows a child's swing. The swing is released from point X. Which movement takes one period of the oscillation? 4. A pipe has an approximate length of 60 cm and an approximate internal diameter of 3 cm. Which instruments are the most suitable for measuring accurately the internal diameter and the length?

5. A student measure the thickness of 20 sheets of paper with a micrometer. The diagram shows the reading on the micrometer. What is the average thickness of one sheet of paper?

6. Which quantity is a base quantity?

7. The length of copper pipe, of uniform cross-section and several meters long, carries water to a tape. Measurements are taken to determine accurately the volume of copper in the pipe. Which instrument are used?

8. What is the order of magnitude of the diameter of the human hair? 10¯

9. A pendulum swings backward and forward passing through Y, the middle point of the oscillation. The first time the pendulum passes through Y, the stopwatch is started. The 21st time the pendulum passes through Y, the stopwatch is stopped. The reading of the stopwatch is T. What is the period of the pendulum?

10. What is the correct order of magnitude for the diameter of the earth and for the diameter of an atom?
 Diameter of Earth Diameter of atom A 10 Gm 0.1 um B 10 Gm 0.1 nm C 10 Mm 0.1 um D 10 Mm 0.1 nm

11. Vernier calipers are used to measure the diameter of a ball bearing. Diagram 1 shows the caliper when the jaws are closed. Diagram 2 shows the calipers when the ball bearing is between the jaws. What is the diameter of the ball bearing?

12. The bob of a simple pendulum is pulled to one side and then released. The motion during its wings is shown on the graph. What is the value of the period of the pendulum?

The time taken for a pendulum to swings from position X to its position Y of maximum displacement is 1.5 s. How many complete periods of the pendulum are there in one minute?

14. Which instrument is used to measure directly is the circumference of a golf ball?

15. A micrometer is used to measure the thickness of the metal sheet. Diagram 1 shows the reading on the micrometer when it is tightened with nothing between the jaws. Diagram 2 shows the reading taken with the metal sheet between the jaws. What is the thickness of the metal sheet?

16. A student measures the thickness of a coin using A micrometer screw gauge. The following steps are carried out but are in the wrong order. 1. Turn the ratchet unit a 'click' is heard.
2. Take the reading on the thimble.
3. Place the coin between the anvil and the spindle.
4. Take the reading on the sleeve.
5. Turn the thimble to close the anvil and the spindle.What is the correct order?

17. Which pair of units both measure the same quantity? 