Physics - Mechanics-I, Download PDF Question Paper 2021 for B.Sc., B.A 1st Semester Previous years Examination.

B.A., B.Sc. (General) 1st Semester Examination

Physics - Mechanics-I

Paper:- A

Time: 3 Hours] [Max. Marks: 44

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Download "Physics - Optics and Laser-II " Question Paper PDF of B.Sc. 4th Semester Previous Years Paper for Students.

B.Sc. (General) 4th Semester
Physics
Paper - B: Optics and Laser-II 

Time Allowed: Three Hours

Maximum Marks: 22 

Note: - Attempt two questions from Section I, two questions from Section II, and six parts of the question in Section III. Only non-programmable calculators are allowed to be used.

SECTION-I 

1. (a) Explain stimulated emission, spontaneous emission, and induced absorption. Derive the relation between Einstein's spontaneous and stimulated emission coefficients.

(b) What are the main features of Laser Light?

II. (a) What do you mean by broadening of spectral lines? Derive an expression for Doppler Broadening. 

(b) Find the Doppler Broadening for 6328Ao laser transition in He-Ne Laser, assuming a single isotope of Ne20 and that the Laser operates at a temperature of 373 K.

III. (a) What is population inversion? Why is it essential and how is it achieved in a Laser? 

(b) Explain the elementary theory of optical cavity.

SECTION-II 

IV. (a) Discuss construction and working of Ruby Laser.

(b) What are the applications of Lasers? 

V. (a) Discuss construction and working of CO2, Laser with a neat labeled diagram. 

(b) Find the possible frequency spread when the transition takes place from the unstable upper state having a lifetime of 10-8 s.

VI. (a) What is Holography? Describe recording of a hologram and reconstruction of the image. How holography is different from ordinary photography? 

(b) What are sources of attenuation of the signal in optical fibers?

SECTION-III 

VII. Attempt any six parts :

(i) Distinguish between LASER and MASER. 

(ii) How does Laser light differ from the light from a filament lamp? 

(iii) Can we obtain light amplification in absence of stimulated emission? 

(iv) Define temporal coherence and spatial coherence. 

(v) Do you think energy conservation is violated in Laser? 

(vi) Define coherence time. (vii) What is Laser pumping?

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Download "Physics - A Statistical Physics and Thermodynamic-II" Question Paper PDF of B.Sc. 4th Semester Previous Years Paper for Students.

B.Sc. (General) 4th Semester
Physics 
Paper: A Statistical Physics and Thermodynamic-II 

Time Allowed: Three Hours

Maximum Marks: 22

Note: - (1) Attempt five questions in all, selecting two each from

Unit I and II. Unit III is compulsory 

(2) All questions carry marks as indicated. 

(3) Non-Programmable Calculators are allowed. 

(4) Logarithmic Tables can be asked.

UNIT-I

I. (a) Find the relation for the entropy of one mole of an ideal gas.

2 (b) Find the change in entropy of one mole of carbon dioxide when its absolute temperature increased by 3 times if the process of heating is : 

(i) Isochoric 

(ii) Isobaric

II. (a) Define and find expressions for Thermo-emf, Peltier co-efficient, and Thomson co-efficient.

(b) The entropy of v= 3.0 moles of an ideal gas increases, by    S = 23 JK-1 due to isothermal expansion. How many times should the volume of the gas be increased or decreased ?

III. (a) How does a Heat pump differ from Refrigerator? Prove that the amount of mechanical energy required to extract a given amount of heat from a cold body increases with a decrease in temperature of the body, for a given temperature of the sink.

(b) A heat engine employing a Carnot cycle with an efficiency of n = 20% is used as a refrigerating machine, the thermal reservoir being the same. Find its refrigerating efficiency €.

UNIT-II 

IV. (a) Derive Clapeyron's equation from Maxwell's relations and explain the change of ice to water on the basis of it.

(b) Making use of Maxwell's thermodynamical relation prove that cooling is produced when the substance which contracts on heating is compressed.

V. (a) What are thermodynamic potentials? What is their significance? Deduce the relation 

(b) Derive thermodynamically an expression for Joule-Thomson Co-efficient. Show that for a perfect gas Joule-Thomson effect vanishes.

VI. (a) Find an expression for the change in temperature of wire when stretched adiabatically.

(b) Prove that the specific heat at constant volume for a Vander Waal gas is equal to the specific heat at constant volume for a perfect gas.

UNIT-III

(Compulsory) 

VII. Attempt any six parts : 

(a) How will the entropy change during the free expansion of a gas?

(b) Find the change in the energy of a system if 300 J of work is done on it, while 65 calories of heat flows out of it. 

(c) Write the Clausius-Claperyron's equation. What is its significance? 

(d) Correct representation of 1st law of thermodynamics is

 

(e) How does free electron gas differ from an ordinary gas? 

(f) Why Seebeck effect is not an independent effect?

(g) Two stars radiate maximum energy at wavelength 3.0x10-5 cm and 5.0x10-7 m respectively. What is the ratio of their temperatures?

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Download "Physics" Question Paper of B.Sc. (Hons.) Biotechnology for B.Sc.1st Semester.

 B.Sc (Hons.) Biotechnology

First Semester

BIOT-Sem-I-V-T: Physics 

Time allowed: 3 Hours  Max. Marks: 67 

NOTE: Attempt five questions in all, including Question No. IX (Unit-III) which is compulsory and selecting two questions each from Unit I -11.

UNIT-1

1. a) State and explain Coulomb law. Two point charges one with charge q at (-,0) and the second with charge - at (d, 0) are placed. Find the electric field at point 'C' whose coordinates are (0, R). (X,Y) refer to coordinates. (2,6)

b) How technology helps us understand the functioning of biological systems. Explain with two examples. (5.4)

II. a) State and explain Gauss law. Find the electric field at any point outside a uniformly charged solid sphere of radius R and total charge q. (2,6)

b) Mycoplasma, smallest bacteria have a radius about 0.1 micrometer and the largest bacteria have a radius about 50 micrometers. What is the surface area-to-volume ratio for each of these? (5,4)

III. a) What is the total capacitance C if three capacitances C. Cz Cs are arranged 

(i) inparallel.

ii) in series. (8)

(b) Explain the equation of continuity. (5,4)

IV. a) An infinite plane carries a uniform surface charge o. Find its electric field at any point perpendicular to the sheet. (8)

b) Obtain the expression for energy stored in a capacitor. (5,4)

UNIT -II

V. a) Using Fresnel Biprism arrangement how can one determine the wavelength of monochromatic light. (8)

b) Many interferences leads to diffraction. Explain. (5,4)

VI. a) How does a telescope works? Obtain the expression for its resolving power. (8) 

b) Distinguish Fraunhofer diffraction and Fresnel diffraction. (5,4)

VII. a) What is the Compton effect? Obtain the expression A2 (1-сos %), where mc symbols have their usual moaning. (8)

b) Explain the working of electron microscope.(5,4) 

VIII. a) Explain the phenomena of radioactivity. What are the five kinds of radioactive decays? Explain in detail. (8)

b) What is phase velocity? What is group velocity? When are they equal? (5,4)

                                            Unit- III

IX. Attempt the following:

a) The distance between two cities is 1440 Km by road. How far is this in miles? (2) 

b) Express Ohm's law in vector form. (2)

c) Explain the term polarization. (2) 

d) What is i) half-life ii) mean life of a radioactive substance. (2)

e) Explain concept of fluorescent microscope. (2)

f) State Uncertainty principle (2)

g) The proton that is the nucleus of the hydrogen atom attracts the electron that orbits it. Relative to this force, does the electron attracts the proton with less force, with more force with the same amount of force? Explain. (1,4)

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Physics-Vibrations, Waves & E.M. Theory-I Question Paper Download for B.A and Bsc General 1st Semester, Download Previous Years Question Paper for Students.

B.A./B.Sc. (General) 1st Semester
Physics
Paper-B: Vibrations, Waves & E.M. Theory-I 

Time Allowed: Three Hours) (Maximum Marks: 22 

Note:-

(1) Attempt five questions in all, selecting two  questions each from Section-A and B. Section-Cis compulsory 

(2) Use of a non-programmable calculator is allowed.

SECTION-A 

1. (a) Discuss composition of two SHM perpendicular to each other and periods are in the ratio 1:2. 

(b) A body stands on a platform which vibrates simple harmonically in a vertical direction at a frequency of 5 Hz. Show that the body loses contact with the platform when displacement exceeds 10-2 meters. 3, 1.5 

II. (a) Write and solve the differential equation for a damped LCR circuit and discuss the oscillatory discharge of the capacitor. 

(b) Find the frequency and quality factor of a circuit having

L = 2 mH, C = 5 uF and R = 0.2 ohm. 3, 1.5

III. What is a compound pendulum? Derive an expression for its time period. What is the condition for time period to be a minimum? 4.5 

SECTION-B 

IV. (a) Find expression for the quality factor of a forced oscillator in terms of resonance absorption band width. 

(b) What is mechanical impedance of a forced oscillator? Write expression for it, explaining the meaning of each term. 3.5.1 

V. (a) Discuss the oscillations of two pendulums coupled through a spring of stiffness S and write the equations of motion of the system in different cases. 

(b) Show that in a resonant LCR circuit, the maximum potential drop occurs across the capacitor at a frequency:   

VI. Write down the equation of motion of a forced oscillator being driven by an alternating force F cos wt. Explain its steady state behaviour and hence describe the behaviour of displacement versus driving force frequency. 4.5

SECTION-C 

VII. Attempt any eight parts :

(a) Explain the role of restoring force and inertia in SHM. 

(b) A mass of 1 kg is attached to a spring of stiffness constant 25 Nm-1 Find the natural frequency. 

(c) How the logarithmic decrement is related to quality factor? 

(d) Is energy stored in a forced oscillator? Explain 

(e) What is meant by transient state of a forced harmonic oscillator? 

(f) What is the effect of damping on the natural frequency of an oscillator? 

(g) Why does an LC circuit usually produce damped oscillations? 

(h) Why the glass windows may be broken by the far away explosion? 

(i) Is the transformer loose or tight coupled, whose mutual inductance is 0.3 H and self-inductance of primary and secondary are 0.25 H and 4.0 H respectively? 

(j) What is importance of normal modes of vibration? 1/2x8=4

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