Chapter -1.1 "Physical quantities and measurement techniques" - Short Question
1.1 Physical Quantities and Measurement Techniques Q1. State the SI unit of length. Answer: metre (m) Q2. Name the instrument used to measure length in the laboratory. Answer: Ruler or metre rule Q3. What is the smallest division on a typical school ruler? Answer: 1 mm Q4. Define parallax error. Answer: Error caused when the scale is read from an angle instead of at eye level. Q5. How can parallax error be avoided when using a ruler? Answer: Read the scale at eye level directly above the marking. Q6. Why should repeated measurements be taken? Answer: To reduce random error and improve reliability. Q7. A student measures from 2.0 cm to 7.5 cm. Calculate the length. Answer: Length = 7.5 − 2.0 = 5.5 cm Q8. Why is it better to measure 10 sheets of paper instead of one sheet? Answer: To reduce percentage uncertainty. Q9. Where is the length of a pendulum measured from? Answer: From pivot to centre of the bob. Q10. State one precaution when measuring a curved object. Answer: Use a string to ...