TS Inter 1st Year Physics Study Material Chapter 1 Physical World

Telangana TSBIE TS Inter 1st Year Physics Study Material 1st Lesson Physical World Textbook Questions and Answers.

TS Inter 1st Year Physics Study Material 1st Lesson Physical World

Very Short Answer Type Questions

Question 1.
What is Physics? [TS Mar. ’16]
Answer:
Physics is a branch of science which deals with the study of nature and natural phenomena.

Question 2.
What is the discovery of C.V. Raman? [AP Mar. ’18, 14; May 18, 16, 14; TS Mar. ’19, ’18, ’17]
Answer:
C.V. Raman’s contribution to physics is Raman effect. It deals with scattering of light by molecules of a medium when they are excited to vibrational energy levels.

Question 3.
What are the fundamental forces in nature? [TS May ’18]
Answer:
There are four fundamental forces in nature that govern the diverse phenomena of the macroscopic and the microscopic wu.m. These are the ‘gravitational force’, the ‘electromagnetic force’, the ‘strong nuclear force’, and the ‘weak nuclear force’.

Question 4.
Which of the following has symr etry?
a) Acceleration due to gravity.
b) Law of gravitation.
Answer:
Acceleration due to gravity varies from place to place. So it has no symmetry.
Law of gravitation has symmetry, because it does not depend on any physical quantity.

Question 5.
What is the contribution of S. Chandra Sekhar to Physics?
Answer:
S. Chandra Sekhar discovered the structure and evolution of stars. He defined “Chandra Sekhar limit” which is used in the study of black holes.

Question 6.
What is beta (β) decay? Which force is a function of it?
Answer:
In β-decay the nucleus emits an electron and an uncharged particle called neutrino.

β – decay is due to weak nuclear forces.

❖ Some physicists and their major contributions

Name	Major contribution/ Discovery
1. Archimedes	Principle of buoyancy, Principle of the lever
2. Galileo Galilei	Law of inertia
3. Isaac Newton	Universal law of gravitation; Laws of motion, Corpuscular theory of light; Reflecting telescope.
4. C.V.Raman	Inelastic scattering of light by molecules.
5. Edwin Hubble	Expanding universe
6. Hideki Yukawa	Theory of nuclear forces
7. S. Chandrasekhar	Chandrasekhar limit, structure and evolution of stars
8. Michael Faraday	Electromagnetic induction laws
9. James Clark Maxwell	Electromagnetic theory – light – electromagnetic waves
10. J.J.Thomson	Electron
11. Albert Einstein	Explanation of photoelectric effect and theory of relativity
12. R.A.Millikan	Measurement of charge of electron.
13. Ernest Rutherford	Nuclear model of atom
14. John Bardeen	Transistors; Theory of super conductivity.

❖ Fundamental forces of nature

Name	Relative strength (N)
1. Gravitational force	10-39
2. Weak nuclear forces	10-13
3. Electromagnetic forces	10-2
4. Strong nuclear forces	1

 

❖ Fundamental constants of Physics

Physical constant	Symbol	Value
1. Speed of light in vacuum	C	3 × 108 meter/sec
2. Planck’s constant	h	6.63 × 10-34 joule.sec
3. Molar gas constant	R	8.31 joule/mole.K
4. Avogadro’s number	NA	6.02 × 1023/ mol
5. Boltzmann’s constant	K	1.38 × 10-23/mol
6. Gravitational constant	G	6.67  10-11 Newton.m2/kg2
7. Mechanical equivalent of heat	J	4.185 joule/cal.
8. Triple point of water	Ttr	273.16 K
9. Density of water at 20° C	dω	103kg/m3
10. Density of mercury	dm	13.6 × 103 kg/m3
11. Density of dry air at N.T.P.	da	1.293 kg /m3
12. Specific heat of water	sω	1 cal./gm/°C
13. Latent heat of ice	Lf	80 cal./gm
14. Latent heat of steam	Lυ	540 cal/gm (or 539)
15. √5 = 2.236, √3 = 1-732, √10 = 3.162, loge 10 = 2.3026
16. π = 3.14, π2 = 9.87, √π = 1.7772, √2 = 1.414

❖ Conversion factors:
1 metre – 100 cm
1 millimeter – 10^-3m
1 inch – 2.54 × 10^-2m
1 micron (µ) – 10^-4cm
1 Angstrom (A°) – 10^-8cm
1 fermi (f) – 10^-13 cm
1 kilometer – 10³ m
1 light year – 9.46 × 1015 m
1 litre – 10³cm³
1 kilogram – 1000 gm
1 metricton – 1000 kg
1 pound – 453.6 gm
1 atomic mass
unit (a.m.u) 1.66 × 10^-27 kg
1 a.m.u – 931 MeV
1 day – 8.640 × 10⁴ seconds
1 km/hour – \(\frac{5}{18}\) m/sec (or)
0.2778 meter/sec.
1 Newton – 10⁵ dynes
1 gm wt – 980.7 dynes
1 kg.wt – 9.807 Newton
1 Newton/meter² – 1 pascal

1 Pascal – 10 dyne/cm²
1 Joule – 10⁷ erg
1 kilo watt hour – 3.6 × 10⁶ joule
1 electro volt (ev) – 1.602 × 10^-19 joule
1 watt – 1 joule / sec
1 horse power (HP) – 746 watt
1 degree (° ) – 60 minute (‘)
1 Radian – 57.3 degree ( ° )
1 Poise – 1 dyne . sec / cm²
1 Poiseuille – 10 poise
(Newton, sec/m² (or) Pascal sec.)

❖ Important Prefixes:

❖ The Greek Alphabet:

❖ Formulae of geometry :
1. Area of triangle = \(\frac{1}{2}\) × base × height
2. Area of parallelogram = base × height
3. Area of square = (length of one side)²
4. Area of rectangle = length × breadth
5. Area of circle = πr² (r = radius of circle)
6. Surface area of sphere = 4πr² (r = radius of sphere)
7. Volume of cube = (length of one side of cube)³
8. Volume of parallelopiped = length × breadth × height
9. Volume of cylinder = πr²l
10. Volume of sphere = \(\frac{4}{3}\)πr³
Circumference of square = 4l
11. Volume of cone = \(\frac{1}{3}\) πr²h
12. Circumference of circle = 2πr

❖ Formulae of algebra:
(a + b)² = a² + b² + 2ab
(a – b)² = a² + b² – 2ab
(a² – b²) = (a + b) (a – b)
(a + b)³ = a³ + b³ + 3ab (a + b)
(a – b)³ = a³ – b³ – 3ab (a – b)
(a + b)² – (a – b)² = 4ab
(a + b)² + (a – b)² = 2(a² + b²)

❖ Formulae of differentiation:
1. \(\frac{d}{dx}\) (constant) = 0
differentiation with respect to x = \(\frac{d}{dx}\)
2. \(\frac{d}{dx}\) (xⁿ) = n x^{n – 1}
3. \(\frac{d}{dx}\) (sin x) = cos x
4. \(\frac{d}{dx}\) (cos x) = – sin x dx

❖ Formulae of Integration:
Integration with respect to x = ∫dx
1. ∫dx = x
2. ∫xⁿ dx = r n + 1
3. ∫sin x dx = cos x + c
4. ∫cos x dx = sin x + c

❖ Formulae of logarithm :
1. log mn = (log m + log n)
2. log\(\frac{m}{n}\) = (log m – log n)
3. log mⁿ = n log m

❖ Value of trigonometric functions :

❖ Signs of trigonometrical ratios :
sin (90° – θ) = cos θ ; sin (180° – θ) = sin θ
cos (90° – θ) = sin θ ; cos (180° – θ) = – cos θ
tan (90° – θ) = cot θ ; tan (180° – θ) = – tan θ

❖ According to Binomial theorem :
(1 + x)ⁿ ≈ (1 + nx) if x < < 1

❖ Quadratic equation:
ax² + bx + c = 0