Nature Of Physical World And Measurement

Question 1

Scientific investigation

Answer 1

The process of finding the answers to the queries.

Question 2

Reductionism

Answer 2

An attempt to explain a macroscopic system in terms of its microscopic constituents

Question 3

Classical mechanics

Answer 3

The study of forces acting on bodies whether at rest or in motion

Question 4

Classical physics

Answer 4

Refers to traditional physics that was recognized and developed before the beginning of the 20th century.

Question 5

Thermodynamics

Answer 5

The study of the relationship between heat and other forms of energy.

Question 6

Otpics

Answer 6

The study of light

Question 7

Electricity and magnetism

Answer 7

The study of electricity and magnetism and their mutual relationship

Question 8

Astrophysics

Answer 8

The branch of physics which deals with the study of the physics of astronomical bodies.

Question 9

Relativity

Answer 9

One of the branches of theoretical physics which deals with the relationship between space, time and energy particularly with respect to objects moving in different ways.

Question 10

Quantum mechanics

Answer 10

The study of the discrete nature of phenomena at the atomic and subatomic levels

Question 11

Atomic physics

Answer 11

The branch of physics which deals with the structure and properties of atom.

Question 12

Nuclear physics

Answer 12

The branch of physics which deals with the structure and properties and reaction of the nuclei atoms.

Question 13

Condensed matter physics

Answer 13

The study of the properties of condensed materials. It covers the basics of material science, which aims at developing new material with better properties for promising applications

Question 14

Condensed materials,

Answer 14

Solids, liquids, and those intermediate between them and dense gas.

Question 15

High energy physics

Answer 15

The study of nature of the particles.

Question 16

Measurement

Answer 16

The comparison of any physical quantity with its standard unit.

Question 17

Physical quantities

Answer 17

Quantities that can be measured, and in terms of which, laws of physics are described are called phys quantities

Question 18

Fundamental or base quantities

Answer 18

The quantities which cannot be expressed in terms of any other physical quantities.

Question 19

Derived quantity

Answer 19

Quantities that can be expressed in terms of fundamental quantities are called derived quantities

Question 20

Unit of the quantity

Answer 20

An arbitrarily chosen standard of measurement of a quantity, which is accepted internationally is called unit of the quantity

Question 21

Fundamental or base units

Answer 21

The units in which the fundamental quantities are measured are called fundamental or base units.

Question 22

Derived units

Answer 22

The units of measurement of all other physical quantities which can be obtained by a suitable multiplication or division of powers of fundamental units are called derived units

Question 23

System of units

Answer 23

A complete set of units which is used to measure all the kinds of fundamental and derived quantities is called a system od units.

Question 24

One metre

Answer 24

It is the length of the path travelled by the light in vacuum in 1/299,792,458 of a second.

[1983]

Question 25

One kilogram

Answer 25

One kilogram is the mass of the prototype cylinder of platinum iridium alloy [ whole height is equal to its diameter,] preserved at the International Bureau of Weights and Measures at Serves, near Paris, France. [1901]

Question 26

One second

Answer 26

It is the duration of 9,192,631,770 periods of radiation corresponding to thr transition between the two hyperfine levels of the groud state of Caesium-133 atom [1967]

Question 27

One ampere

Answer 27

One ampere is the constant current which when maintained in each of the two straight parallel conductors of infinite length and negligible cross section, held one metre apart in vacuum shall produce a force per unit length 2 × 10-⁷ N/m between them. [1948]

Question 28

One kelvin

Answer 28

One kelvin is the fraction [1/273.16] of the thermodynamic temperature of the triple point of the water. [1967]

Question 29

Triple point of water

Answer 29

It is the temperature at which saturated vapour, pure water and melting ice are all in equilibrium. It is 273.16 K

Question 30

One candela

Answer 30

It is the luminous intensity in a given direction, of a source that emits monochromatic radiation of frequency 5.4 ×10¹⁴ Hz and that has a radiant intensity of 1/683 watt/steradian in that direction. [1979]

Question 31

Science

Answer 31

Science is the systematic organization of knowledge gained through observation, experimentation and logical reasoning.

Question 32

Scientific method

Answer 32

A step-by-step approach in studying natural phenomena and establishing laws which govern these phenomena.

Question 33

Unification

Answer 33

An attempt to explain diverse physical phenomena with a few concepts and laws is unification

Question 34

Acoustics

Answer 34

The study of production and propagation of sound waves

Question 35

What is technology

Answer 35

The application of knowledge for practical purposes in various fields to invent and produce useful products or to solve problems is know as technology.

Question 36

Macrocosm

Answer 36

It refers to a large world in which both objects and distances are large. Ex: large objects like the galaxy, stars, Sun, Earth, Moon and their distances constitute a macrocosm

Question 37

Microcosm

Answer 37

It refers to a small world in which both objects and distances are small-sized. Objects like atoms, protons, neutron, electron, bacteria and their distances constitute a microcosm

Question 38

Screw gauge

Answer 38

It is an instrument used for measuring accurately the dimensions of objects upto a maximum of about 50 mm

Question 39

Vernier caliper

Answer 39

A vernier caliper is a versatile instrument for measuring the dimensions of an object.