Question

Match the physical quantities given in column A to their S I units given in
column B :
(A) (B)
(a) Pressure (i) cubic metre
(b) Temperature (ii) kilogram
(c) Density (iii) pascal
(d) Mass (iv) kelvin
(e) Volume (v) kilogram per cubic metre

NCERT Class IX
Sciences - Exemplar Problems

Chapter 1. Matter in our Surroundings

Answer 1

A) Pressure----Pascal
B)Temperature----- Kelvin
C)Density-------kilogram per cubic meter
D)Mass----kilogram
E)Volume-----cubic meter

Answer 2

The given items are matched as follows:-

a) - (iii), b) - (iv), c) - (v), d) - (ii), e) - (i)

• SI units are standard units of measurement made as relative quantities by the International System of Units.
• It has been defined for seven basic quantities:-

1. Mass - kilogram, depicted by "kg"
2. Length - metre - "m"
3. Time - seconds - "s'
4. Amount of Substance - moles - "mol"
5. Luminous Intensity - Candela - "cd"
6. Temperature - Kelvin - "K"
7. Current - Amperes - "A"

• All these can be utilized to derive SI units of other quantities.
• Volume can be calculated by using the formula - length × base × height i.e m × m × m = m³ ∴ SI unit of Volume = m³.
• Density can be calculated by using the formula - mass/Volume = kg/m³ ∴ SI unit of Density = kg/m³.
• Pressure can be calculated by using the formula - Force/area, Area = length × length = m², Force = mass × acceleration i.e kgm/s²(acceleration = velocity/time - m/s²).
• ∴ SI unit of Force = kgm/s² called 1 Newton - represented as "N".
• ∴SI unit of Pressure = N/m² called Pascal.