Ncert Physical World,units And Dimensions,errorsin Measurements

Question 1

Hydroelectric power

Answer 1

Conversion of gravitational potential energy into electrical energy

Question 2

Steam engine

Answer 2

Laws of thermodynamics

Question 3

Mediating particle of electromagnetic force

Answer 3

Photon

Question 4

Systemic or controlled errors

Answer 4

Cause is known

Question 5

SI system consists

Answer 5

7 fundamental units

2 supplementary units

Question 6

Relative strength of fundamental forces

Answer 6

Gravitational: 10^-39
Weak nuclear: 10^-13
Electromagnetic: 10^-2
Strong nuclear: 1

Question 7

Werner Heisenberg

Answer 7

Quantum mechanics
Uncertainty principle

Germany

Question 8

Mediating particle of weak nuclear force

Answer 8

Boson

Question 9

Photocell

Answer 9

Photoelectric effect

Question 10

Aeroplanes

Answer 10

Bernoulli’s principle of fluid dynamics

Question 11

Wolfgang Pauli

Answer 11

Exclusion principle

Austria

Question 12

Mediating force of strong nuclear force

Answer 12

Gluon

Question 13

Mediating particle of gravitational force

Answer 13

Graviton

Question 14

Production of ultra high magnetic field

Answer 14

Superconductivity

Question 15

Laser

Answer 15

Light amplication, by stimulated emissions of radiation

Question 16

Albert Einstein

Answer 16

Explanation of photoelectric effect
Theory of relativity

Germany

Question 17

T.V and radio

Answer 17

Generation, propagation and detection of EM waves.

Question 18

Gross errors

Answer 18

Human carelessness

Question 19

Nuclear reactor

Answer 19

Controlled nuclear fission

Question 20

C.G.S other name

Answer 20

Gaussian system

Question 21

James clerk maxwell unified

Answer 21

Electricity,magnetism and optics.
Showed that light is an electromagnetic wave

1873

Question 22

No of SF in 23000.

Answer 22

5

Question 23

Absolute error

Answer 23

Difference between true value and individual measured value.

Question 24

S. Chandrashekhar

Answer 24

Chandrashekhar limit
Structure and evolution of stars

India

Question 25

No of SF in 23000

Answer 25

2

Question 26

Fusion test reactor (Tokamak)

Answer 26

Magnetic confinement of plasma

Question 27

Edwin Hubble

Answer 27

Expanding universe

U.S.A

Question 28

Weakest fundamental force

Answer 28

Gravitational force

Question 29

Rocket propulsion

Answer 29

Newton’s laws of motion

Question 30

Non reflecting coating

Answer 30

Thin film optical interference

Question 31

Ernest Rutherford

Answer 31

Nuclear model of atom

New Zealand

Question 32

Electric generators

Answer 32

Faraday’s laws of EMI

Question 33

Electron microscope

Answer 33

Wave nature of electrons

Question 34

Abdus Salam

Answer 34

Unification of weak and electromagnetic forces

Pakistan

Question 35

C.V Raman

Answer 35

Inelastic scattering of light by molecules

India

Question 36

Neils Bohr

Answer 36

Quantum model of hydrogen atom

Denmark

Question 37

Louis Victor de Broglie

Answer 37

Wave nature of matter

France

Question 38

Random error

Answer 38

Cause is unknown

Question 39

F.P.S other name

Answer 39

British engineered system

Question 40

Particle accelerators

Answer 40

Motion of charged particles in electromagnetic field

Question 41

SI system other name

Answer 41

Rationalised MKS system

Question 42

James Chadwick

Answer 42

Neutron

U.K

Question 43

J.J. Thomson

Answer 43

Electron

U.K

Question 44

Bose Einstein condensate

Answer 44

Trapping and cooling of atoms by laser beams and magnetic fields

Question 45

R.A. Millikan

Answer 45

Measurement of electronic charge

U.S.A