Measurements – Very Short Q&A (IIT Foundation Class 8)
Q1: What does physics deal with?
Physics deals with nature and its laws.
Q2: Give one example showing the importance of measurement.
Time taken by runners in a race is measured to decide the winner.
Q3: Define physical quantities.
Quantities that can be measured, like mass, length, volume, etc.
Q4: What is a unit?
A well-defined standard used for measuring a physical quantity.
Q5: State any two characteristics of a good unit.
It should be well-defined and reproducible.
Q6: What is a fundamental quantity? Give examples.
Independent quantities like mass, length, time, temperature.
Q7: What is a fundamental unit? Give examples.
Units of fundamental quantities, e.g., kilogram, metre, second.
Q8: What is a derived quantity? Give examples.
Quantities dependent on fundamental ones, e.g., area, volume, velocity.
Q9: What is a derived unit? Give examples.
Units of derived quantities, e.g., m², m³, m/s.
Q10: Name the four main systems of units.
FPS, CGS, MKS, and SI system.
Q11: What is the SI unit of mass, length, and time?
Mass → kilogram (kg), Length → metre (m), Time → second (s).
Q12: Define one metre as per modern definition.
It is 1,650,763.73 times the wavelength of orange light from krypton.
Q13: Define one kilogram.
Mass of a platinum-iridium block kept at the International Bureau of Weights and Measures.
Q14: Define one second (modern definition).
Time taken by cesium-133 atom to complete 9,192,631,770 vibrations.
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