PHYSICAL QUANTITIES AND MEASUREMENT
TEXTBOOK EXERCISE QUESTIONS
1.1Encircle the correct answer from the given choices.
The number of base units in SI are:
ii. Which one of the following unit is not a derived unit?
iii. Amount of a substance in terms of numbers is measured in:
iv. An interval of 200µs is equivalent to:
(a) 0.2 s
(b) 0.02 s
(c) 2 x 10-4 s
(d) 2 x10-6 s
Which one of the following is the smallest quantity?
(a) 0.01 g
(b) 2 mg
(c) 100 µg
(d) 5000 ng
vi. A student claimed the diameter of a wire as 1.032 cm using vernier calipers. Up to
what extent do you agree with it?
(a) 1 cm
(b) 1.0 cm
(c) 1.03 cm
(d) 1.032 cm
vii. Significant figures in an expression are:
(a) All the digits
(b) All the accurately known digits
(c) All the accurately known digits and the first doubtful digit
(d) All the accurately known and all the doubtful digits
1.2: What is the difference between base quantities and derived quantities? Give
three examples in each case.
The quantities on the basis of which other
quantities are expressed are known as base
Length, time, mass
Physical quantities which can be described
in terms of base quantities are known as
Force, area, volume
1.3: Pick out the base units in the following:
Joule, Newton, kilogram, hertz, mole, ampere, meter, Kelvin, coulomb and watt.
• Kilogram (unit of mass)
• Mole (unit of quantity of substance)
• Ampere (unit of electric current)
• Meter (unit of length)
• Kelvin (unit of temperature)
1.4: Find the base quantities involved in each of the following derived quantities:
(a) Speed (b) Volume (c) Force
Ans. (a) Speed