NCERT Class 11 Physics Solutions: Chapter 2 - Unit and Measurement Part 1

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Image Showing the Metric Unit of Measure

Question: 2.1

Fill in the blanks

(a) The volume of a cube of side 1 cm is equal to ________

(b) The surface area of a solid cylinder of radius 2.0 cm and height 10.0 cm is equal to ________

(c) A vehicle moving with a speed of 18 km covers ________ m in 1 s

(d) The relative density of lead is 11.3. Its density is ________ g . Or ________ kg .

Answer: 2.1

(a)

1 cm

  • Volume of the cube
  • But, 1

1

  • Hence, the volume of a cube of side 1 cm is equal to

(b)

  • The total surface area of a cylinder of radius r and height h is

Given that,

(c)

  • Using the conversion,

=

  • Therefore, distance can be obtained using the relation:

  • Hence, the vehicle covers 5 m in 1 s.

(d)

  • Relative density of a substance is given by the relation,
  • Relative density
  • Density of water = 1 g/
  • Density of lead

  • Again, 1 g