Physical quantities and measurement are fundamental concepts in science that enable the quantification and comparison of various physical phenomena. Physical quantities are classified into base quantities, such as length, mass, time, electric current, temperature, intensity of light, and the amount of substance, which serve as the foundation for derived quantities like area, volume, speed, and force. Measurement involves assigning a numerical value to these quantities using standardized units from the International System of Units (SI), ensuring consistency and accuracy in scientific communication. The process of measurement also incorporates the use of significant figures to reflect precision and uncertainty, making it essential for conducting experiments and interpreting results in various scientific fields
What is the International System of Units (SI)?
The International System of Units (SI) is a standardized system of measurement used globally, which defines units for base quantities to ensure consistency and accuracy in scientific communication.
Why is it important to use significant figures in measurements?
Significant figures are important because they indicate the precision of a measurement and help convey the uncertainty associated with it, ensuring clarity and accuracy in scientific reporting.
How is the unit of area derived?
The unit of area is derived from the base unit of length; for example, area is measured in square meters (m²), which is obtained by squaring the meter (m).
What is the least count of a measuring instrument?
The least count of a measuring instrument is the smallest value that can be measured accurately with that instrument, reflecting its precision.
What instruments are commonly used for measuring length?
Common instruments for measuring length include rulers, measuring tapes, Vernier calipers, and micrometer screw gauges.
What is the SI unit of mass?
a) Gram
b) Kilogram
c) Pound
d) Ounce
Answer: b) Kilogram
Which of the following is a base quantity?
a) Volume
b) Speed
c) Temperature
d) Density
Answer: c) Temperature
What is the derived unit for pressure in the SI system?
a) Pascal
b) Newton
c) Joule
d) Watt
Answer: a) Pascal
Which instrument is used to measure the volume of a liquid?
a) Ruler
b) Measuring cylinder
c) Thermometer
d) Stopwatch
Answer: b) Measuring cylinder
What does the prefix "milli-" represent in the SI system?
a) 1,000
b) 0.001
c) 100
d) 10
Answer: b) 0.001