# Measurements and Experiments | Extra Questions

## Measurements and Experiments

Q1. Define physical quantity. Give examples.

Ans: The type of quantity that can be measured is called a physical quantity. Example: length, time, mass etc.

Q2. Name the three systems of the unit and state their various fundamental units.

Ans: Three systems of unit and their fundamental units:

a) M.K.S. system: In this system, the unit of length is meter (m), unit of mass is kilogram (kg) and unit of time is second (s).

b) C.G.S. system: In this system, the unit of length is centimeter (cm), unit of mass is gram (g) and unit of time is second (s).

c) F.P.S. system: In this system, the unit of length is foot (ft), unit of mass is pound (lb) and unit of time is second (s).

Q3. Name two units of length that are bigger than a meter.

Ans: Astronomical unit (A.U.) and kilometre (km)

Q4. How is nanometre related to Angstrom?

Ans: one nanometer is equal to ten times of an angstrom ie 1 nm = 10 Å

Q5. State two units of mass bigger than a kilogram. Give their relationship with the unit kilogram.

Ans: The units ‘quintal’ and ‘metric tonne’ are two units of mass bigger than ‘kilogram’.
1 quintal = 100 kg
1 metric tonne = 1000 kg

Q6. ‘The year 2024 will have February of 29 days.’ Is this statement true?

Ans: Yes, it is true.

Q7. What is a simple pendulum?

Ans: A small metallic bob suspended by a light inextensible string from rigid support, such that it is free to oscillate without friction about a point, is called a simple pendulum.

Q8. Define the terms:

a) oscillation

Ans: The to and fro motion of the pendulum is called oscillation.

b) amplitude

Ans: The maximum displacement of the pendulum, i.e., the displacement between the mean position and the extreme position, is called its amplitude.

c) frequency

Ans: The number of oscillations made by the pendulum in one second is called its frequency of oscillation.

d) time period as related to a simple pendulum.

Ans: The time taken by an oscillating pendulum to make one complete oscillation is called its time period.

Q9. Draw a neat diagram of a simple pendulum. Show the effective length and one oscillation of the pendulum.

Q10. How are the time period T and frequency f of a simple pendulum related to each other?

Ans: Frequency is inversely proportional to the time period ie f=1/T​