Physics Classes

Author: Nayan Jha

  • Kinetic theory of gases

    Kinetic theory of gases

    Kinetic theory of gases

    This assignment contains all important questions of the chapter kinetic theory of gases

    Biot -savart's law

    KINETIC THEORY OF GASES

    1. What are the basic assumptions of kinetic theory of gases ? on their basis, derive an expression for the pressure exerted by an ideal gas.
    2. What is meant by degrees of freedom? State the law of equipartition of energy. Hence calculate the values of molar specific heats at constant volume and pressure for monoatomic , diatomic and triatomic gases.
    3. Calculate the kinetic energy of one mole of argon at 127⁰ given that N =6.02×1023 mol and k=1.381 x10-23 mol-1K-1
    4. Calculate the number of degrees of freedom for one mole of diatomic gas at N.T.P
    5. Calculate the number of degrees of freedom of 1 cm3 of helium gas at N.T.P.
    6. A vessel contains argon gas at 127⁰ find the average kinetic energy of argon molecule, if Boltzmann’s constant, k=1.38 x 10-23 j mol -1 K-1
    7. Calculate the total kinetic energy of 1g of helium at 27⁰C Given that R =8.31 mole -1 K-1.
    8. At what temperature is the r.m.s velocity of a hydrogen molecule equal to that of a oxygen molecule at 47⁰C ?
    9. Give the kinetic interpretation of temperature and define absolute temperature.
    • 10. If three molecules have velocities 0.5,1 and 2km s-1 respectively, calculate the relation between the root mean square speed and average speed.
    • 11. Calculate the temperature at which the r.m.s velocity of a hydrogen will be equal to 8km/hr. given that R =8.31 j mole -1.
    • 12.Calculate the r.m.s velocity of CO2 molecules at N.T.P. given, R=8.31 j mol -1 K-1 .
    • 13. Calculate the r.m.s velocity of hydrogen at N.T.P. given that density of the gas is 9×10-5 g cm -3.
    • 14. Find the temperature at which the root mean square velocity of a gas is double than that its value at 0 ⁰C , pressure remaining constant.
    • 15. The molar gas volume at S.T.P. is 22.4 litre and Avogadro number is 6.023×1023. (a) calculate the number of gas molecules per unit volume,
    • 16. Draw a graph to show the variation of V2 rms with absolute temperature .
    • 17. When an ideal gas undergoes an isothermal expansion, the pressure of the gas in the encloser falls. Why?
    • 18. Two identical cylinders contains helium at 2.5 atmosphere and organ at 1 atmosphere. Find pressure if both the gases are filled in one of the cylinders?
    • 19. The temperature of argon, kept in vessel, is raised by 1⁰C at constant volume. The total heat supplied to the gas is a combination of translational energies. Find their respective shares.
    • 20. A gas mixture consist of 2 moles of oxygen and 4 moles of argon at temperature T. find total internal energy of the system, when vibrational modes are rejected.

     

  • JEE (main) january 2020 Question paper

    JEE (main) january 2020 Question paper

    JEE  (main) January 2020 Question paper

    Physics classes by Nayan Jha publishing the question paper of JEE (main) January   2020 asked in 9th of January second seating . the questions are memory based and it is taken from the any other different – different sites , and it posted after a correct view by the Nayan Jha ( director of physics classes by Nayan jha) . if there is iny wrong solution in the given paper then please message on the site , and give your feedback please , having saw your query ill try to correct my answer and i’ll  try to provide most correct answer .

    this year there are 25 questions in all sections ( physics/chem./ math ).

     To dawnload question paper and its solution click here-jee2010 9th january

    Having saw the  standard of the question papers this year it is possible that cutoff  Jee 2020   may be near about 75 marks (all together) . The  standard of questions  in physics was little bit tougher  than average questions ( as it is asked previous years). The standard of questions was different for different day and different periods .  students  who solved questions more than 8 ( eight) is good for physics point of view , if such students will go for next examination ( April 2020) definitely  will do batter with applying little bit more effort .

    physics classes by nayan jha provides assignment  for the objective questions of all chapters ( individually) , it will help the students preparing for JEE( main) / NEET and other board examinations. to download objective questions in all chapters visit – www.physicsclasses.online

  • Important questions of oscillations and waves

    Important questions of oscillations and waves

    Important questions of oscillations and waves

    This assignment contains all important questions of oscillations and waves , it will help the students preparing for the final class examination and prepare entire chapters in short time .

    1. What do you mean by SHM ? Find expression for its displacement, velocity and acceleration , also write their phase difference .
    2. What is meant by symmetric & Doppler effect?
    3. How does the frequency of a tuning fork change, when the temperature is increase?
    4. Tube a has both ends open, whole tube B has one end closed otherwise the two tubes are identical. what is the ratio of fundamental frequency of the tubes A and B?
    5. When we start an empty bucket with water, the pitch of the sound produced foes on changing. Why?
    6. A sine wave is travelling in a medium. What is the minimum distance between two particles always have same speed?
    7. Two waves of the same frequency and amplitude superpose to produce a resultant disturbance of the same frequency. What is the phase difference between the waves?
    8. A spring balance has a scale that reads from 0 to 50 kg. the length of the scale is 20cm. a body suspended from this spring, when displaced and released, oscillates with a period of 0.60 s. what is the weight of the body?
    9. A spring of mass 2.50 kg is under a tension of 200 N. the length of the stretched string is 20.0 m. if a transverse jerk is struck at one end of the string, how long does the disturbance take to reach the other end.
    10. A policeman on duty detects a drop of 15in the pitch of the horn of a motor car as it crosses him, if the velocity of sound is 330m/s, calculate the speed of the car.
    11. The third overtone of a closed organ pipe is found to be in unison with the first overtone of an open pipe. Find the ratio of the length of the pipes.                                                                                                                                                                                                                    TO download OSCILLATIONS and WAVE important questions click here-.
  • Sample paper for class -12th (physics)

    Sample paper for class -12th (physics)

      Sample paper  for class -12th (physics)

    This is the first sample paper designed on the basis of latest CBSE pattern , by physics classes by nayan jha. student may solve the entire question paper for  the practice well before the examination. I also want to inform that such kind of question paper will be provided every week ( on sunday) student can download all question paper and test himself after solving all question papers.

    Sample paper -1 .

    Sec-A   mark-1

    1. Two charges 3×10-5 and 5×104C are placed at a distance 10cm from each other. Find the value of electrostatic force acting between them.                                (a)5×1011N(b)40×1011N(c)180×109N(d)5×1010N
    2.  When charge is supplied to a conductor, its potential depends upon                                                        (a)The amount of charge  (b)Geometry and size of conductor        (c)Both (a) & (b)         (d)Only on (a)
    3. Kirchhoff’s II law for the electric network is based on:                                                                                 (a)Law of conversation of charge  (b)Low of conversation of energy    (c)Low of conversation of angular momentum    (d)Low of conversation of mass

     

    1. In a whetstone’s bridge, all the four arms have equal resistance R. if resistance of the galvanometer arm is also R, then equivalent resistance of combination is              (a)R(b)2R(c)R/2(d)R/4

     

    1. In a certain reason of space, electric filled E vector and magnetic filled b vector are perpendicular to each other. An electron inters perpendicularly to both the fields and move undeflected. The velocity of electron is                                                                                                                                           (a)E/B    (b)B/E     (c)E vector x B vector      (d)E vector. B vector

     

    1. How does the focal length of a convex lens changes if mono chromatic red light is used instead of violet light?                                                                                                                                                              (a)Focal length is increased when red light is used                                                                                     (b)Focal length is decreases when red light is used                                                                                      (c)Focal length is remain same when red light is used                                                                                   (d)Not depends on colour of light.
    2. the phenomenon of polarization is exhibited by                                                                             (a)longitudinal wave(b)matter wave(c)transverse wave(d)mechanical wave

     

    1. which of the following is correct for” Malus Law”                                                                                       (a)I=I2v cos2 θ(b)I=Iv cos2 θ(c)I=I2v sin2 (d)I=Iv tan-1 θ
    2. the theory on the basis of photoelectric effect can be explained:                                                       (a)Corpuscular theory(b)Wave theory(c)Electromagnetic theory(d)Quantum theory

     

    10.When alpha particle are sent through a thin gold foil, most f beam go straight through the foil because                                                                                                                                                                          (a)Alpha particles are positively charged(b)Alpha particles are is more than mass of electron(c)Most of the part of an atom is empty space(d)Alpha particles moves with high velocity

     TO download complete question paper click here -Sample paper-1

    To download 2nd sample paper click here – sample paper-2

    To download 3rd sample paper click here- sample paper-3

    To download 4th sample paper click here -sample paper-4

  • Objective questions of ray optics

    Objective questions of ray optics

    Objective questions of ray optics

    this assignment will provide the important Objective questions of ray optics for  students preparing for class-12th board examination and for the students preparing for JEE/NEET and other competitive examinations.

    Reflection and Refraction of Light at Plane Surface ( Objective questions of ray optics)

    1. When light travels from glass to air, the incident angle is and the refraction angle is .the true relation is :(a)θ 1 =θ 2      (b)  θ 1 >θ2  (c)θ1 <θ2  (d)Not predictable
    2. Two mirrors are kept at 60 to each other and a body is placed in the middle.The total number of images formed is:(a)Three(b)Four (c)Five (d)Six
    3. If an object is placed unsymmetrically between two plane mirrors inclined at an angle 72 ,then the total number of images formed is:(a)5   (b)4    (c)2   (d)infinite
    4. If an object is placed symmetrically between two plane mirrors, inclined at an angle of 72 .than the total total number of images formed is:(a)5 (b)4 (c)2 (d)Infinite

    5) A ray of light is incident on a plane mirror at an angle of incidence of 30⁰ ,the deviation

    Produced by the mirror is :

    (a) 30 ⁰ ( b) 60⁰

    (c) 90⁰ (d) 120

    6) when a ray of light enters a glass slab from air:

    (a) its wavelength decreases

    (b) its wavelength decreases

    (c) its frequency increases

    (d) neither wavelength nor frequency changes

    7) When a light enters from air to water, then its:

    (a) frequency increases and speed decreases

    (b) frequency is the same but the wavelength is smaller in water then in air:

    (c) frequency is same but wavelength in water is greater than in air

    To download complete assignment of ray optics click here-objective ray optics

  • Objective questions of capacitance

    Objective questions of capacitance

    Objective questions of capacitance

    This assignment contains all important  objective questions of capacitance, it will be beneficial for the students preparing for class 12th board examination or preparing for JEE/NEET.

    Before to solve this assignment student must solve the assignment of its previous chapter electric field and potential, to download the assignment of objective questions of electric field and potential click here.

    Capacitance

    1. There are 27 drops of a conducting fluid. Each has a radius r and they are charged to a potential V0. These are combined to from a bigger drop. Its potential will be:
    • (a)V0      (b) 3V0    (c) 9V0          (d) 27V0
    1. 1000 small water drops each of radius r and charge q coalesce together to from one spherical drop. The potential of the bigger drop is larger than that of the smaller one by a factor:
    • (a)1000        (b) 100         (c) 10          (d) 1
    1. The capacitance of a parallel plate condenser does not depend upon:
    • (a)area of the plates
    • (b)medium between the plates
    • (c)distance between the plates
    • (d)metal of the plates
    1. The force between the plates of a parallel plate capacitor of capacitance C and distance of separation of the plates d with a potential difference V between the plates is:
    • (a)CV2/2d (b) C2V2/2d2    (c) C2V2/d2      (d) V2d/C
    1. A parallel plate capacitor is made by stacking n equally spaced plates connected alternately. If the capacitance between any two plates is C, then the resulting capacitance is:
    • (a)C    (b) nC         (c) (n-1)C        (d) (n+1)C
    1. Two parallel metal plates carry charge +Q and -Q respectively. A test charge q0 placed between them experiences a force F. Now the separation between the plates is doubled, then the force on the test charge will be:
    • (a)F         (b) 2F             (c) F/2              (d) F/4
    1. A 2μF capacitor is charged to a potential of 200 V and then isolated. When it is connected in parallel with a second capacitor which is uncharged, the common potential becomes 40 V. The capacitance of the second capacitor is:
    • (a)2μF        (b) 4μF        (c) 8μF       (d) none of these
    1. Three capacitors of capacitance 12μF each are available. The minimum and maximum capacitance which may be obtained from these are:
    • (a)12μF, 36μF (b) 4μF, 12μF    (c) 4μF, 36μF   (d) 0μF, ꚙμF

    To download entire assignment of objective questions of electric field click here -objective questions of Capacitance

     

    To solve the assignment of important objective  questions of electric current click here.

    electric- current
    electric- current

     

  • Important questions of thermodynamics

    Important questions of thermodynamics

    Important questions of thermodynamics

    This assignment contains all important questions of thermodynamics. It will help the students of class 11th to practice the entire chapter of thermodynamics for the final examination of class 11th , in cbse/icsc and   all state board examinations.

    IMPORTANT QUESTIONS  OF THERMODYNAMICS

    1. During an adiabatic process, the pressure of a gas is found to be proportional to cube of its absolute temperature what is the ratio of Cp/Cv ?
    2. Can a room be cooled by opening the door of a refrigerator in a closed room?
    3. Which molecules ice at 0⁰C or water at 0⁰C have greater potential energy and why?
    4. (a) can the temperature of system be increases without heating it? (b) can heat be added to a system without increasing its temperature?
    5. A refrigerator, whose coefficient of performance β is 5 extract heat from the cooling compartment at the rate of 250 j per cycle.
    • (a)How much work per cycle is required to operate the refrigerator cycle? (b) how much heat per cycle is discharged to the room which acts as high temperature reservoir?
    1. A piston divides a closed gas cylinder gas into two parts. Initially the piston is kept pressed such that one part has a pressure p and volume 5V and the other part has pressure 8p and volume v; the piston is now left free. Find the new pressure and volume for the isothermal and adiabatic prosses.
    2. Two car not engine A and B ate operated in series. The first one A receive heat at 800k and rejects to a reservoir at TK. The second engine B receives the heat rejected by the first engine and in turn
    3. A mass of diatomic gas (=1.4) at a pressure of 2 atmosphere is compressed adiabatically, so that its temperature rises from 27⁰C to 927⁰. What is the pressure of the gas in the final state.
    4. State and explain the isothermal process, derive the expression for work done in isothermal process.
    5. State and explain the adiabatic process, derive the expression for work done in adiabatic process.

     

    To download entire IMPORTANT QUESTIONS OF  THERMODYNAMICS question paper click here-

  • Objective questions of alternating current

    Objective questions of alternating current

    Objective questions of alternating current

    LC-OSCILLATOR

    This assignment (Objective questions of alternating current),provide the important objective questions of the chapter alternating current ,which is important for the students preparing for class-12th board examination or , other competitive examinations (JEE/NEET)

    Before to solve this assignment (Objective questions of alternating current), student should solve the assignment of objective questions of electromagnetic induction-

    1. A direct current of 5 amp is superimposed on an alternating current I = 10sin ɷt flowing through a wire. The effective value of the resulting current will be:
    • (a)(15/2) amp     (b) 5√3 amp  (c) 5√5 amp      (d) 15 amp
    1. In an AC circuit, a resistance of R ohm is connected in series with an inductance L. If phase angle between voltage and current is 45°, the value of inductive reactance will be:
    • (a)R/4
    • (b)R/2
    • (c)R
    • (d)cannot be found with the given data
    1. Resonance frequency of L – C circuit is:
    • (a)1/2π √LC       (b) 1/2πLC   (c) 1/2π √L/C   (d) 1/2π √LC
    1. In L-C-R series AC circuit, the phase angle between current and voltage is:
    • (a)any angle between 0 and ± π/2
    • (b)π/2
    • (c)π
    • (d)any angle between 0 and π
    1. In an L-C-R circuit, the capacitance is made one-fourth, when in resonance, so that the circuit remains in resonance?
    • (a)4 times    (b) (1/4) times       (c) 8 times        (d) 2 times

    TO download complete assignment of Objective questions of alternating Current- click here-

  • Objective questions of electromagnetic induction

    Objective questions of electromagnetic induction

    Objective questions of electromagnetic induction-

    This assignment contains Objective questions of electromagnetic induction, which will help the students to prepare for class 12th board examination and other competitive exams like JEE/NEET.

    Before to solve this assignment students has to solve assignment of magnetic effect of current, to solve the questions of magnetic effect of current click here

    1. Lenz’s law is a consequence of the law of conservation of:
    • (a)charge      (b) mass     (c) momentum      (d) energy
    1. The law of electromagnetic induction have been used in the construction of a:
    • (a)galvanometer (b) voltmeter    (c) electric motor   (d) generator
    1. A cylindrical bar magnet is kept along the axis of a circular coil. On rotating the magnet about the axis, the coil will have induced in it:
    • (a)a current (b) no current       (c) only an em        (d) both an emf and a current
    1. A horizontal straight conductor when placed along south-north direction falls under gravity; there is:
    • (a)an induced current from south to north direction
    • (b)an induced current from north to south direction
    • (c)no induced emf along the length of the conductor
    • (d)an induced emf along the length of the conductor
    1. A car moves on a plane road. Induced emf produced across the axle is maximum when it moves:
    • (a)at the poles (b)moves at equator (c) remains stationary
    • (d) no emf is induced at all

    To download complete assignment of objective questions of electromagnetic induction click here-Electromagnetic Induction

    after solving this assignment of objective questions of electromagnetic induction student should solve the assignment of objective questions of alternating current . To download the complete assignment of objective questions of alternating current click here –

  • Objective questions of magnetism and matter

    Objective questions of magnetism and matter

    Objective questions of magnetism and matter

    This assignment contains all type objective questions of magnetism and matter. it will be helpful for the students preparing for class 12th board examination or other competitive examinations like JEE/ NEET .

    Magnetism and matter

    1. With the tangent galvanometer it is desirable to have a deflection near 45°; then the percentage error:
    • (a)is less in the reading of deflection
    • (b)is negligible in the reading of deflection
    • (c)is less in the measurement of current
    • (d)is large in the measurement of current
    1. The sensitivity of a moving coil galvanometer depends on:
    • (a)the angle of deflection
    • (b)the earth’s magnetic field
    • (c)torsional constant of the spring
    • (d)the moment of inertia of the coil
    1. An ammeter can be converted into a voltmeter by connecting:
    • (a)a high resistance in series
    • (b)a low resistance in parallel
    • (c)a low resistance in series
    • (d)a high resistance in parallel
    1. In a moving coil galvanometer the deflection of the coil θ is related to the electric current I by the relation:
    • (a)I ꭀ tan θ       (b) I ꭀ θ                   (c) I ꭀ θ2                      (d) I ꭀ √θ
    1. A voltmeter of range 2V and resistance 300 Ω cannot be converted into ammeter of range:
    • (a)1 A      (b) 1 mA             (c) 100 mA              (d) 10 mA
    1. The effect due to uniform magnetic field on a freely suspended magnetic needle is as follows:
    • (a)both torque and net force are present
    • (b)torque is present but no net force
    • (c)both torque and net force are absent
    • (d)net force is present but not torque
    1. A voltmeter has a resistance of G ohm and range V volt. The value of resistance used in series to convert it into voltmeter of range nV volt is:
    • (a)nG       (b) (n – 1)G               (c) G/n                   (d) G/(n – 1)
    1. An ammeter has a resistance of G ohm and a range of I The value of resistance used in parallel to convert it into an ammeter of range nI amp is:
    • (a)nG       (b) (n – 1)G               (c) G/n               (d) G/(n – 1)
    1. To reduce the range of a voltmeter, its resistance need to be reduced. Which of the following resistance when connected in parallel will convert it into a voltmeter of range (V/n)?
    • (a)nR0 (b) (n + 1)R0     (c) (n – 1)R0        (d) None of these

    To download entire  assignment click here- Magnetism and matter objective