Study of Logarithmic Table and other Tables

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For 11th and 12th Students

 USE OF LOGARITHMIC TABLES & OTHER MATHEMATICAL TABLES

In Physics practicals and numerical problems we are required to use the logarithmic tables for calculations. 

The logarithmic tables are used for multiplications, divisions, squaring and finding the roots of the numbers. Logarithm of a number consists of the following two parts:

(i) Characteristics (C):- Integral part 

(ii) Mantissa:- Decimal part.

logarithm of a number = Characteristic + Mantissa

For example : log 49 = 1.6902 

In the answer before decimal number 1 is the Characteristics and .6902 is mantissa.

(A) Determination of the Characteristics:–

(i) Characteristics for numbers  greater than or equal to 1:

 The Characteristics of such number is positive.

Rule: Count the number of digits (d) in the integral part of the given number, subtract 1 from it and you will get the characteristics (C). 

i.e. C = (d-1). 

Some examples:

(ii) Characteristics of a number less than 1:

Such numbers have only decimal part. The characteristics of such number is negative.

Rule: Count the number of zeros (z) immediately following the decimal part; add 1 to it and you will get the characteristics i.e. C and is read as bar C.

Examples:-

(B) Determination of Mantissa: 

Rule: To find the mantissa, first convert the given number in four figure number by approximation. For example: 273.16 ⇒ 273.2

Divide given four figure number into three groups as: 

Refer the logarithmic table and search two digit number i.e. 27 given in the first box in the first column the of the Logarithmic table. 

Consider the row with the number 27. In this row, the number under the column headed by Third digit i.e. 3 is 4362. 

 In the same row, the number in the Mean Difference column headed by 2 is 3. 

 Add this number 3 to 4362 gives 4365. The mantissa for the logarithm of the given number is 0.4366. The characteristics of the number 273.2 is 2. 

 Therefore the

 log 273.2 = 2 + 0.4365 = 2.4365

Part –B: Antilogarithm (Abbreviation: Antilog)

It is the reverse process of logarithm that is you are given the logarithm of a number in the form ⇒ 

log N = Characteristics + Mantissa

 i.e. log 273.2 = 2.4365

From 2.4365, we have to find original number N (i.e. 273.2).

∴ Antilog (log N) = N

 Rule: Consider the four figure mantissa part in the decimal part (with the decimal point) of 2.4365 (i.e. .4365)

Now refer the Antilogarithmc Table, use the same method as you use for finding the logarithm.

Now add add number 3 to 2729 gives as 2729+3 = 2732

Use the following rules, to find the number of digits in the integral part of the number. i.e. Position of Decimal point in the final answer.

RULES: (1) If the characteristic is zero the number of digit in the integral part of the number is one.

 (2) If the characteristic is positive, the number of digits in the integral part of the number is one more than the characteristics. (i.e. C + 1). 

(3) if the characteristic is negative the number of zeros following the decimal point 

( before the first significant figure) is one less than the numeral value of the characteristics.

For Example: If the characteristic is 2, put the decimal point after first three digits. If the characteristic is bar 3, write two zeros between decimal point and first digit. 

 ∴ Antilog (2.4365) = 273.2 OR 2.732 × 10²                                                                    

LOG AND ANTILOG OF SOME NUMBERS

Laws (Theorems)of Logarithms 

PART:C 

Use of Reciprocal Table

Take the first for digits of one digit- integer number. Find the first two digit number with decimal point between in the first column of the reciprocal table. Follow the same procedure as for logarithm of number, but the number from the main difference column has to be subtracted.

For Example: Reciprocal of 3.372 = 1/ 3.372, find 3.3 in the first column; proceed along in row to the column headed 7 the figure there is 2967 then we proceed along the same row to the mean difference part and find the figure in the column headed 2.

 It is 2.  Subtract it from 2967 and we get 2965.

∴ 1/ 3.372 = 0.2965

Rules: 1) Reciprocal of a number more than one:

 Experess the given number in the form of First two digit number with decimal point between multiplied by a factor of appropriate + ve power of 10 and find the reciprocal. 

Example: 1/751.6 = 1/ 7.516× 10² = 0.1331 × 10-³ = 0.001331

2)  Reciprocal of a number less than 1:

Experess the given number in the form of First two digit number with decimal point between multiplied by a factor of appropriate - ve power of 10 and find the reciprocal. 

Example: 1/ 0.03216= 1/ 3.216× 10-² = 0.3109× 10² = 31.09

EXERCISE-2:

Find the reciprocals of :     

(i) 73.5  (ii) 591.1  (iii) 0.4216    (iv) 0.08192    (v) 0.003572 

EXERCISE-3 

Use Trigonometric Tables, Natural Sines, Natural Cosines Natural Tangents Tables. 

Note: The method of using the table is similar to that for logarithm of a number.                                                                      

For sine & tangent table, add the mean difference but for cosine table subtract the mean difference. 

1) Find sin θ  for following the angles :

     (a) 30⁰ (b) 60⁰ 36' (c) 24⁰ 15' 

2) Find cos θ for following the angles : 

     (a) 40⁰ (b) 54⁰ 12' (c) 23⁰ 25' 

3) Find tan θ for following the angles : 

     (a) 45⁰ (b) 39⁰ 24' (c) 50⁰ 7' 

EXERCISE-4  Inverse of trigonometric values: 

Find the angle θ  in the following cases: 

 (i)  sin θ =   0.1739                         (ii) cos θ = 0.9390       

 (iii) tan θ = 1.2550 

## ANSWERS:  

EXERCISE-1 

1) 3526     2) 15.81  3) 67.08        

4) 13.81    5) 76.96  6) 25.01          7) 3.004    8) 0.001541    

9) 12.92     10) 16.21        

11) 1.984 × 10⁶    12) 5.001×10¹²  13) 3.005          14) 5.961          

 

EXERCISE-2 

(i) 0.136 ×10 -¹ = 0.01361      

(ii)  0.1692 × 10 -² = 0.001692      (iii)  0.2378 × 10 ¹ = 2.378            (iv)  0.1221  × 10 ² = 12.21            (v) 0.2803 × 10 ³ = 280.3 

EXERCISE-3 

1) (a)  0.5000 (b)  0.8712                   (c) 0.4107 

2) (a)  0.7660 (b)  0.5850                  (c) 0.7179                                    3) (a)  1.0000   (b)  0.8214                (c) 1.1967 

EXERCISE-4 

(i)  θ = 10⁰ 1'    (ii)  θ =  20⁰ 7'        (ii) θ =  51⁰ 27 '                       

*******END*******

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        12th PHYSICS IMP  

   PRACTICE QUESTIONS 

    FOR MAHARASHTRA 

           HSC BOARD 

         CHAPTER 11 TO 16

Chapter 11. Magnetic Materials 

1. Explain the directional characteristic of a bar magnet. State its use.

2. Obtain an expression for orbital magnetic moment of an electron revolving about the nucleus of an atom. 

                   OR

Show that orbital magnetic moment of an electron revolving about the nucleus of an atom is proportional to its angular monmentum

3. State formula for gyromagnetic ratio. Find the gyromagnetic ratio of Electron. ( Given: me = 9.1 ×10⁻³¹kg, and e= 1.6 × 10⁻¹⁹ C).

4. What is the gyromagnetic ratio of an orbital electron ? State its dimensions and the SI unit.

5. State the vector form of the formula of orbital magnetic moment of an electron revolving about the nucleus of an atom. State why it is Negative? 

6. Obtain the expression for Bohr Magneton. State its value with unit.

7. Explain magnetization of a material.

8. Define magnetization. State its dimensions and the SI unit.                          OR

   Define magnetization. State its formula and SI unit.

9. Define magnetic intensity. State its dimensions and the SI unit.

10. What is the magnetic susceptibility of a medium?

11. Is magnetic susceptibility a dimensionless quantity? Why?

                *************

CHAPTERR 12.           ELECTROMAGNETIC   INDUCTION 

1) Express Faraday-Lenz’s law of electromagnetic induction in an equation form.

2) Determine the motional emf induced in a straight conductor moving in a uniform magnetic field with constant velocity.

3) Find an expression for the power expended in pulling a conducting loop out of a magnetic field.

4) What are eddy currents? State applications of eddy currents.

5) Explain and define the self inductance of a coil.

6) State and define the SI unit of self inductance. Give its dimensions.

7) Obtain an expression for the self inductance of a solenoid.

8) Derive the expression for the energy stored in the magnetic field of an inductor.

9) Obtain an expression for the self inductance of a solenoid.

10) Explain and define mutual inductance of a coil with respect to another coil.

11) Show that the mutual inductance for a pair of inductively coupled coils/circuits of self inductances L1 and L₂ is given by M = K√L1L₂ , where K is the coupling coefficient.

12) What is a transformer? State the principle of working of a transformer.

13) Describe the construction and working of a transformer with a neat labelled diagram.

14) Distinguish between a step-up and a step-down transformers.  

           *****************

      Chapter 13 AC CIRCUITS 

1) What is the average or mean value of an alternating emf? Obtain the expression for it. 

2) What is the rms value of an alternating current? Find the relation between the rms value and peak value of an alternating current that varies sinusoidaily with time.

3) What is a phasor? What is a phasor diagram ? Illustrate it with an example.

4) An alternating emf e = e₀ sin ωt is applied to a resistor of resistance R. 

Write the expression for the current through the resistor. Show the variation of emf and current with ωt. 

Draw a phasor diagram to show emf and current.

5) Draw a Phasor diagram showing e and i in the case of a purely inductive circuit.

6) An alternating emf is applied to an LR circuit. Assuming the expression for the current, obtain the expressions for the applied emf and the effective resistance of the circuit. Assume the inductor and resistor to be ideal. 

Draw the phasor diagram showing the emf and current.

7) Draw the impedance triangle for a series LCR AC circuit and write the expressions for the im-pedance and the phase difference between the emf and the current.

8) What is an acceptor circuit ? State its use.

9) Explain electrical resonance in an LC parallel circuit. Deduce the expression for the resonant frequency of the circuit.

10) What is a rejector circuit? State its use.

11) How are oscillations produced using an inductor and a capacitor?

12) Explain electrical resonance in an LCR series circuit. 

Deduce the expression for the resonant frequency of the circuit.

             **************

Chapter 14  Dual Nature of Radiation and Matter

1) With a neat diagram, describe the apparatus to study the characteristics of photoelectric effect.

2)  In the experiment to study photoelectric effect, describe the effects of the frequency and intensity of the incident radiation on the photoelectric current, for a given emitter material and potential difference across the photoelectric cell.

3) Define (1) Threshold frequency (2) Threshold wavelength (3) Stopping potential.

4) State the characteristics of photoelectric effect.

5) Define photoelectric work function of a metal.

6) Write Einstein’s photoelectric equation and explain its various tends. How does the equation explain the various features of the photoelectric effect?

7) Explain wave-particle duality of electromagnetic radiation.

8) State the de Broglie hypothesis and the de Broglie equation.

9) Derive an expression for the de Broglie wavelength associated with an electron accelerated from rest through a potential difference V. Consider the nonrelativistic case.

10) Derive an expression for the de Broglie wavelength.

            ************

Chapter 15 Structure of     Atoms and Nuclei 

1) Explain Thomson’s model of the atom. What are its drawbacks?

2) Explain Rutherford’s model of the atom. State the difficulties faced by Rutherford’s model of the atom.

3) State and explain the formula that gives wavelengths of lines in the hydrogen spectrum.

4) State the Postulates of Bohr’s atomic model.

5) speed of an electron in a Bohr orbit. Hence, show that it is inversely proportional to the principal quantum number.

6) Derive an expression for the radius of the nth Bohr orbit in an atom. Hence, show that the radius of the orbit is directly proportional to the square of the principal quantum number.

7) Show that the energy of the electron in the nth stationary orbit in the hydrogen atom is Eₙ = -RHch/n².

8) Draw a neat, labelled energy level diagram for the hydrogen atom. Hence explain the different series of spectral lines for hydrogen.

9) Obtain the ratio of the longest wavelength of spectral line in the Paschen series to the longest wavelength of spectral line in the Brackett series.

10) State the limitations of Bohr’s atomic model.

11) On the basis of the de Broglie hypothesis, obtain Bohr’s condition of quantization of angular momentum.

12) State the law of radioactive decay and express it in the exponential form.

OR 

State the law of radioactive decay. Hence derive the relation N = N₀e-λt, where the symbols have their usual meanings.

13) Define half-life a radioactive element and obtain the relation between half-life and decay constant.

14) What is meant by average life or mean life of a radioactive species ? How is it related to the half-life?

               ************

Chapter 16 Semiconductor Devices 

1)  Draw a neat block diagram of a dc power supply and state the function of each part.

                      OR 

With the help of a block diagram, explain the scheme of a power supply for obtaining dc output voltage from ac line voltage.

2) Explain full wave rectifier. State advantages of it.

3) Distinguish between a half-wave rectifier and full-wave rectifier.

4) Explain ripple in the output of a rectifier. What is ripple factor?

5) Explain the action of a capacitive filter with necessary diagrams.

6) What is a photodiode? Explain the I-V characteristics of a photodiode.

7) What is (i) dark current (ii) dark resistance of a photodiode?

8) State any  advantages and disadvantages of a photodiode.

9) State any two applications of photodiodes.

10) What is a solar cell ? State the principle of its working. State any four uses of solar cells.

11) State the material selection criteria for solar cells.

12) What is a light-emitting diode (LED)? Describe with a neat diagram the construction of an LED.

13) State any four disadvantages of an LED. State any four applications of LEDs.

14) Explain the working of an npn transistor with a neatly labelled circuit diagram.

15) Draw a neat labelled circuit diagram to study the characteristics of a transistor in common- emitter configuration.

16) What is an amplifier? Draw a neat circuit diagram of a transistor CE- amplifier and explain its working. 

17) Define the following logic gates :

(1) AND

(2) OR

(3) NOT.

Give the logic symbol, Boolean expression and truth table of each.

18) Define the logic gates (1) NAND (2) NOR.

Give the logic symbol, Boolean expression and truth table of each.

How are the above gates realized from the basic gates?

*****************************

       ALL THE BEST

IMPORTANT PRACTICE QUESTIONS 12 TH PHYSICS 

HSC MAHARASHTRA BOARD 2024

Chapter 6 to 10

Chapter 6. Superposition of Waves 

1. Equation stationary wave on stretched string and condition of nodes and antinodes ?

2. State the properties of Stationary wave.

3. Distinguish between a) progressive wave and stationary wave 

b) Free and Force vibration?

4. Obtain the expression for the frequency of the first three modes of vibration of stretched string between two rigid support with the help of neat labelled diagram. Hence show that all harmonics are present  in these vibrations.

5. Draw the neat labelled diagram of the first three modes of vibration of air column in a pipe open at one end (or closed at one end). 

Obtain the formule for the frequency of the first three modes of  vibration of air column in the same pipe. Also in this case show that odd harmonics are present. 

6. Obtain an expression for the frequency of the first three modes of vibration of air column in the pipe open at both end with neat labelled diagram. Also in this case show that even harmonics are present. 

7. Show that the fundamental frequency of vibration of the air column in a pipe open at both ends is double that of a pipe of the same length and closed at one end.

8. Two organ pipes closed at one end have the same diameters but different lengths. Show that the end correction at each end is where the symbols have their usual meanings.

9. What are beats? Define (1) the period of beats (2) beat frequency.

10. Explain the production of beats and deduce analytically the expression for beat frequency.

                    OR 

 Discuss analytically the formation of beats and show that 

(1) the beat frequency equals the difference in frequencies of two interfering waves

(2) the waxing and waning occur alternately and with the same period.

11. Explain any two applications of beats.

          ###*********###

Chapter 7. Wave Optics

1 Give a brief account of Huygens’ wave theory of light. State its merits and demerits.

2. State Huygens’ principle.

3. Explain the construction and propagation of a plane wavefront using Huygens’ principle.

4. Explain the construction and propagation of a spherical wavefront using Huygens’ principle.

5.Explain the phenomenon of polarization of light by reflection. 

                      OR 

   Explain Brewster’s law.

6. Describe with a neat labelled ray diagram the Fraunhofer diffraction pattern due to a single slit. Obtain the expressions for the positions of the intensity minima and maxima. Also obtain the expression for the width of the central maximum.

7. In Young’s double-slit experiment, a glass slide of refractive index ng and thickness b is placed in front of one of the slits. 

What happens to the interference pattern and fringe width ?

 Derive an expression for the positions of the bright fringes in the interference pattern.

8. State and explain Rayleigh’s criterion for minimum resolution.

              ###********###

PART 4

Chapter 8. Electrostatics 

1.Obtain an expression for the electric field intensity at a point outside a charged conducting spherical shell.

Hence, obtain an expression for the electric intensity 

(i) on the surface of (i.e. just outside) the spherical conductor. 

(ii) inside the spherical conductor.

2. Obtain an expression for the electric field intensity at a point outside an infinitely long charged cylindrical conductor.

3. Obtain an expression for the electric field intensity at a point outside a uniformly charged thin infinite plane sheet.

4. Obtain an expression for the electric potential energy of a system of two isolated point charges.

5. Obtain an expression for the electric potential at a point due to an isolated point charge.

6. Derive an expression for the electric potential at a point due to a short electric dipole. Hence, write the expression for the electric potential at a point 

(i) on the dipole axis 

(ii) on the dipole equator.

7. Derive an expression for the potential energy of a system of two point charges.

8. Obtain an expression for the potential energy of a configuration of N point charges.

9. Derive an expression for the electric potential energy of an electric dipole in a uniform electric field. 

                        OR

Derive an expression for the total work done in rotating an electric dipole through an angle θ in a uniform electric field.

10. Derive an expression for the effective or equivalent capacitance (capacity) of a combination of a number of capacitors connected in series.                          OR

Derive an expression for the effective capacitance of three capacitors connected in series.

11. Explain the effect of a dielectric on the capacitance of a isolated charged parallel-plate capacitor.

Hence, show that if a dielectric of relative permitivity (dielectric constant) k completely fills the space between the plates, the capacitance increases by a factor k.

12. Show that the energy of a charged capacitor is 1/2 CV². Also, express this in other forms. 

                         OR

Derive an expression for the energy stored in a charged capacitor. Express it in different forms.

              ###********###

Chapter 9. Current Elecricity

1 State Kirchhoff’s first law or current law or junction law.

2. What is the sign convention used for Kirchhoff’s first law? Explain with an example.

3. What is the sign convention used for Kirchhoff’s first law? Explain with an example.

4. What is the sign convention used for Kirchhoff’s second law ? Explain with an example.

5. Obtain the balancing condition in case of Wheatstone’s network.

6. Explain with the help of neat circuit diagram, how you determine the unknown resistance by using a meter-bridge.

7. Describe how a potentiometer is used to compare the emfs of two cells by combination method.

8. Describe with the help of a neat circuit diagram how you will determine the internal resistance of a cell by usinhg a potentiometer.

9. State the advantages of a potentiometer over a voltmeter.

10. Explain how a moving-coil galvanometer is converted into an ammeter. Derive the necessary formula.

11. Explain how a moving-coil galvanometer is converted into a voltmeter. Derive the necessary formula.

12. Distinguish between an ammeter and a voltmeter.

           ###*********####

PART 5

Chapter 10. Magnetic Fields due to Eletric Current 

1 (a) State the factors which the magnetic force on a charge depends upon and write its vector cross product relationship. 

    (b) Hence state the expression for the Lorentz force on a charge due to an electric field as well as a magnetic field.

    (c) Hence discuss the magnetic force on a charged particle which is

(i) moving parallel to the magnetic field (ii) stationary.

2. Define the SI unit of magnetic induction from Lorentz force.

3. Obtain an expression for the magnetic force acting on the straight wire carrying a current. Also extend this formula for a wire of arbitrary shape. 

4. Derive an expression for the net torque on a rectangular current-carrying loop placed in a uniform magnetic field with its rotation axis perpendicular to the field.

5. Describe the construction of a suspended-type moving-coil galvanometer with a neat labelled diagram.

6. State working of a moving- coil galvanometer (suspended-coil type).

7. State the Bio-Savart law (Laplace law) for the magnetic induction produced by a current el-ement. Express it in vector form.

8. Using Biot-Savart’s law, obtain the expression for the magnetic induction near a straight infinitely long current-carrying wire.

9. Show that currents in two long, straight, parallel wires exert forces on each other. Derive the expression for the force. 

                      OR

    Derive an expression for the force per unit length between two infinitely long parallel conductors carrying current and hence define the ampere.

10. Obtain an expression for the magnetic induction produced by a current in a wire in the shape of a circular arc at its centre of curvature. 

Hence obtain an expression for the magnetic induction at the centre of a circular coil carrying a current.

11. Derive an expression for the magnetic induction at a point on the axis of a circular coil carrying a current.

12. State and explain Ampere’s circuital law.

13. Using Ampere’s law, obtain an expression for the magnetic induction near a current-carrying straight, infinitely long wire.

14. Using Ampere’s law, derive an expression for the magnetic induction inside an ideal solenoid carrying a steady current.

15. Using Ampere’s law, derive an expression for the magnetic induction inside an ideal toroid carrying a steady current.

              ###********###

 

12th PHYSICS IMP PRACTICE QUESTIONS - 2024

Chapter 1 To 5

FOR MAHARASHTRA HSC BOARD 

IMPORTANT PRACTICE QUESTION for 12TH PHYSICS 

HSC MAHARASHTRA BOARD 2024

● PRACTICE THEORY QUESTIONS FOR 12TH PHYSICS ●

IMPORTANT NOTE: 

1) Please read the board Textbook in detail.

2) Prepare all Definitions, Concepts, Laws, Rules, Properties/ Characteristics, Assumptions Formulae.

3) Prepare all diagrams, constructional diagrams, circuit diagrams, ray diagrams.

4) Following are the practice questions for your board study.

# For Numerical Problems study the Solved Problems from Balbharti PHYSICS Textbook and Solved all Unsolved problems from the Textbook.

PART 1

CHAPTER 1.  Rotational Dynamics 

1. Distinguish Between Centripetal force and Centrifugal force.

2. What is the banking of road and obtain an expression for the maximum/minimum safety speed of vehicles moving along curve horizontal road.

3. Draw the neat labelled diagram of the conical pendulum state the expression for its periodic time and the term of length.

4. A bob tied to a string is whirled in a non-uniform vertical circular motion. Derive the expression for tension in the string at uppermost and lowermost position.

 5. Show that the difference in tensions in the string at the highest and lowest positions is 6 mg.

 6. Show that the K.E of a rotating body about a given axis is equal to 1/2 lω².

7. State and prove the theorem of parallel/perpendicular axes 

8. State and prove the law of conservation of angular momentum.

9. Show that / prove that L =Iα.          

             ## ******** ##

Chapter 2.

Mechanical Properties of Fluids

1. Define a) Intermolecular force b) adhesive force

c) Cohesive force d) Range of molecules e) Surface Film.

2. Explain the phenomenon of surface tension on the basis of molecular theory. 

3. What is Surface energy? Obtain the relation between Surface Tension and surface energy.

4. Define surface tension. State its SI unit and dimensions.

5. Define angle of contact? State its four characteristics.

6. Explain the effect of impurity on S.T?

7. Derive Laplace's law for the spherical membrane of the bubble due to surface tension.

8. Define capillary and capillarity.Obtain the expression for capillary rise or fall ?

9. Define critical velocity. Write the expression for the Reynolds Number.

10. Define Velocity gradient and coefficient of viscosity?

11. Explain Newton’s law of viscosity. Hence define coefficient of viscosity.

12. State the Stokes law. State its formula for Terminal Velocity.

13. Obtain an expression for terminal velocity of a spherical object falling through a viscous fluid.

14. Explain the formation of concave and convex surface of a liquid on the basis of molecular theory.

###*******###

PART 2

Chapter 3. Kinetic Theory of Gases and Radiation

1. On the basis of kinetic theory of gases. Derive an expression for the  

   pressure exerted by a gas.

2. Define R.M.S velocity / speed.

3. Explain Mayers relation for  a) Monoatomic Gas b) Dia-atomic c) polyatomic molecules.

4. Define a) coefficient of absorption b) coefficient of reflection c) coefficient of  

transmission?

5. What is perfectly black body and Draw the labelled diagram?

6. Explain Ferry's black body.

7. Explain black body radiation spectrum in term of wavelength?

8. State and explain a) Wien's displacement law b) Stefan law ?

9. Define emissive power and coefficient of emission of a body?

###*********###

Chapter 4. Thermodynamics 

1. State first law of thermodynamics.

2. State Zeroth law of thermodynamics.

3. Define internal energy. 

4. What is meant by thermal equilibrium? 

OR What is meant by the expression ‘two systems are in thermal equilibrium?

5. Work Done during a thermodynamics process.

6. Explain classification of thermodynamic systems.

7. What is a thermodynamic process? Give an exmple.

8. On the basis of the kinetic theory of gases, explain 

(i) positive work done by a system (ii) negative work done by a system.

9. Obtain an expression for the work done by a gas. OR Show that the work done by a gas is given by.
             

10. What is an isothermal process? Obtain an expression for the work done by a gas in an isothermal process.

11. Explain a) Reversible / Irreversible process 

b) Isothermal process. 

c) Isobaric process. 

d) Isochoric process. 

e ) adiabatics process /  

      cyclic process.

###********###

PART 3

Chapter 5. Oscillations

1. Define linear S.H.M ? Obtain an expression for differential Equation of linear SHM.

2. From differential equation of linear SHM, obtain an expression for acceleration, velocity and displacement of particle in SHM ?

3. Discuss the composition of two SHM along the same path having same period and find the resultant amplitude and initial phase?

4. Deduce the expressions for Kinetic Energy and Potential Energy and total energy of a particle performing SHM.

5. Define Simple pendulum. Derive expression for the period of motion of simple pendulum. Also state on which factor it depends?

6. Define Angular SHM and obtain its differential equation?

HSC PHYSICS - TIPS 25

HSC PHYSICS - TIPS 25

## IMPORTANT PRACTICE QUESTIONS FOR HSC BOARD EXAM 2024— Click the Links

1) For Chapter 1 to 5 

https://ravindrawaykolesciphy.blogspot.com/2024/02/12th-physics-imp-practice-questions.html

2) For Chapter 6 to 10

https://ravindrawaykolesciphy.blogspot.com/2024/02/important-practice-questions-12-th.html

3) For Chapter 11 to 16

 https://ravindrawaykolesciphy.blogspot.com/2024/02/12th-physics-imp-questions-for.html

****************************

HSC (12 वी) Physics प्रश्नपत्रिका सोडविताना घ्यावयाची काळजी

HSC विद्यार्थ्यांसाठी विशेष मार्गदर्शनपर सुचना 

 HSC Board चा Physics paper  सोडविताना विद्यार्थ्यांनी खालील गोष्टी विशेष लक्षात घेवून Paper सोडवावा.

# Board Physics paper च्या 15  दिवसांपूर्वी काय करावे-

15 Days before HSC EXAM

1] प्रत्येक Chapter मधील खालील सर्व मुद्दे (Points) Revise करावीत. 

खालील सर्व मुद्दे समजावून घेऊन लक्षात ठेवा आणि पाठ करा.

Definitions,  State the Laws, Rules, Theorems, Principals , Statements, formulae, Equations, Units, Dimensions, Significance of – ve sign, Sign conventions, Properties/ Characteristics, Examples, Illustrations,Uses, Applications, Types, Processes, Advantages, Disadvantages, Merits, Demerits, Assumptions, Postulates, Limitations, Analogy, Truth Tables, Short note, Distinguish/ Differences between, Infer, Similarities, 

2] आकृत्यांविषयी (Diagrams) महत्त्वाचे:

Diagram pencil ने geometric box चा वापर करून काढाव्यात.

 Textbook मधील सर्व diagrams चा सराव करून तयार करा/लक्षात ठेवा. Diagrams वेगवेगळ्या प्रकारच्या विचारल्या जाऊ शकतात. जसेकी,

General /Science diagram, Vector diagram, FBD ( free body diagram), Vertical section/ Top view/ Side view diagrams, Schematic diagram, Constructional diagram, Mechanical Set-up diagram, Experimental Set-up diagram, Ray diagram, Energy flow diagram, Geometrical diagram, Internal structure of instrument, Schematic structure, Circuit diagram, Block diagram, Symbols, Circuit symbol, Graphs, p- V diagram, Wave form, Phasor diagram इत्यादि सर्व बाबी.

3] Derivations सोडविताना —

 Related diagram pencil ने geometric box चा वापर करून काढावी. Diagram वरून Description/ Explanation लिहावे. Derivation करण्यासाठी आवश्यक त्या Physics, Maths formula, Geometry, Trigonometry चा steps मध्ये योग्य वापर करावा. नंतर final formula, equation, relation derive करून box मध्ये लिहावे.  

4] एक आणि दोन मार्क्सच्या प्रश्नांचा जास्तीत जास्त सराव करावा. 

#हे लक्षात ठेवा:

 प्रश्नपत्रिका 4 Section मध्ये विभागीत केलेली आहे. (Sections– A, B, C & D). प्रश्नपत्रिका सुरुवातीला General Instructions दिलेल्या असतात. त्यांना काळजीपूर्वक वाचाव्यात.

 5] Section A मध्ये Q. 1 अंतर्गत 10 MCQ ( 7 Theory + 3 Numerical problems आणि Q. 2 मध्ये 8  V.S.A.( 6 Theory + 2 Numerical problems असतात. असे एकूण 18 मार्क्सचे प्रश्न असतात.

6] Section B मध्ये Q. 2 ते Q. 14 अंतर्गत 2 Marks चे एकूण 12 प्रश्न 7 Theory + 5 Numerical problems असतात त्यापैकी 16 मार्क्सचे 8 प्रश्न compulsory सोडवायचे असतात.

7] Section C मध्ये Q. 15 ते Q.26  अंतर्गत 3 Marks चे एकूण 12 प्रश्न 7 Theory + 5 Numerical problems असतात. त्यापैकी 24 मार्क्सचे 8 प्रश्न compulsory सोडवायचे असतात.

8] Section D मध्ये Q. 27 ते Q 31 अंतर्गत 4 Marks चे 2 प्रश्न pure Theory questions आणि  3 प्रश्न (2 मार्क्स theory + 2 मार्क्स Numerical  problems) म्हणजे 4 मार्क्सचेच असतात. त्यापैकी 12 मार्क्सचे कोणतेही 3 प्रश्न compulsory सोडवायचे असतात.

9] वरील प्रश्नांची गुणविभागणी पाहता 1 व 2 गुणांच्या प्रश्नांची तयारी केली असता एकूण 46 मार्क्स मिळू शकतात.  

## Numerical Problems  विषयी काही:

Numerical Problems सोडविण्याचे तंत्र आणि मंत्र

Textbook मधील सर्व Physics concept/Terms आणि Formulae  चा अभ्यास करून ती लक्षात ठेवावीत.

Numerical problems (Solved and Unsolved from Exercise)चाच जास्त सराव करा. अधिकची Practice होण्यासाठी इतरही अधिकृत पुस्तकातील problem सोडवण्याचा सराव करावा. 

Numerical Problems सोडवितांना कसे लिहावे: Numerical Problems Presentation in Answer sheet

 दिलेले Numerical Problem  काळजीपूर्वक नीट वाचावा. त्यात दिलेल्या physical quantities च्या values note कराव्या. त्यांना गरजेनुसार एकाच system of unit मध्ये आणाव्यात. त्यातील अटी वाचून mathematical expression मध्ये रुपांतरीत convert करून घ्याव्यात. Problem सोडवण्यासाठी कोणता Physics concept लागेल याचा नीट विचार करावा.

संबंधित Physics formula लिहावा. त्यात values substitute कराव्यात. नंतर सहजपणे simplify करता येत असेल तरच करावे. गरजेनुसार Log calculations करावे. शेवटी Answer लिहून योग्य unit द्यावे. उत्तरला Box करावा.

## प्रश्नपत्रिका सोडविण्याचा सराव:

मागील 5 वर्षाच्या HSC Board च्या (Feb/ July exam) प्रश्नपत्रिका सोडवाव्यात. अधिक सरावासाठी 5 सॅम्पल पेपर्स किंवा मॉडेल पेपर्स घड्याळ लावून वेळेत सोडवावेत आणि आपल्या विषय शिक्षकांकडून त्या तपासून घ्याव्यात. (पेपर कसा लिहावा हे समजून घेण्यासाठी सुरुवातीला दोन किंवा तीन पेपर   Textbook चा वापर करून सोडवावा.)

### Physics board exam च्या दिवशी हे करा:

Paper सोडविताना खालील गोष्टी लक्षात घ्या:

आवश्यक त्या ठिकाणी आकृत्या (Diagrams) काढाव्यात.

10] प्रश्नपत्रिका सोडवताना Section wise क्रमानेच प्रश्न सोडवणे आवश्यक आहे.

11] MCQ चे उत्तर लिहिताना option चा योग्य alphabet  (a) किंवा (b), किंवा (c) किंवा (d) असा लिहून त्यापुढे शब्दात उत्तर लिहिणे अपेक्षित आहे. 

उदा. Q.1 (i) (c) conservation of charge (ii) (a) 2 volt असे लिहावे. 

MCQ मध्ये अजिबात खाडाखोड करू नये. (प्रश्न अजिबात लिहू नये ) तसेच MCQ चे answer Repeat लिहू नये. नंतर पुन्हा लिहिलेल्या MCQ ला गुण मिळतच नाही.(Only first attempt is considered for assessment).

 10) एका मार्कच्या प्रश्नाचे (VSA) नेमके उत्तर एका ओळीतच अपेक्षित आहे. काही वेळा एका शब्दात / अंकात (or number with unit) पण असू शकते.

11) Mcq आणि VSA प्रकारच्या प्रश्नांमध्ये ½ मार्क देण्याची तशी provision किंवा marking scheme नाही. 

12) Numerical problems सोडविताना π ची किंमत 3.142 अशी घेतली तरच मार्क्स मिळतील. 

13) प्रश्नपत्रिका मिळाल्यानंतर सर्व सूचना वाचून घ्याव्यात. त्यातील शेवटच्या सूचनेतील Section A च्या अगोदर दिलेले Physical constants काळजीपूर्वक वाचावे.

14) Numerical problems साठी योग्य Formula लिहून, substitution केले तरी त्यासाठी प्रत्येकी ½ गुण मिळतात. ( काही वेळा 3 Marks च्या Numerical मध्ये प्रत्येकी 1 गुण मिळु शकतो. उत्तर योग्य unit सह नाही लिहिल्यास अथवा चुकीचे लिहिल्यास ½ मार्क कमी केला जातो.

15) प्रश्नपत्रिकेत अधिक प्रश्न असल्याने  कोणते प्रश्न सोडवायचे त्याचे selection विचारपूर्वक करा. जसे की ज्या विद्यार्थ्यांची Theory, चांगली असेल त्यांनी त्यास प्राधान्य द्यावे. आणि ज्या विद्यार्थ्यांस numericals मध्ये चांगली गती असेल त्यांनी त्यास प्राधान्य द्यावे. ज्या विद्यार्थ्यांचा संपुर्ण अभ्यास झाला असेल त्यांनी प्रश्नपत्रिकेतील Derivations आणि Numericals यास जास्त प्राधान्य द्यावे. असे केल्याने पेपर मध्ये चांगला score मिळतो. आणि Paper वेळेच्या आधी लिहुन होतो.

16) त्या त्या section मधील प्रश्न त्या त्या section मध्येच लिहा. एका section मधील question दुसर्‍या section मध्ये लिहून mix करू नका.

17) Choice of questions in Sections B, C & D are very important as student has to attempt 8 questions out of 12  (12 पैकी ८ सोडवायचे आहेत) in section B and C. तसेच  section D  मध्ये 3 out of 5 (5 पैकी 3 सोडवायचे  आहेत). प्रत्येक section मध्ये (B,C, D) 1 ते 2 उपप्रश्न sub question अधिकचे Extra सोडवावीत.

18) Paper representation उत्तम करणेसाठी प्रत्येक प्रश्नाचे heading लिहा आणि अधोरेखित underline करा.

जसे की, Statement, figure, construction, working, uses, Definition, Law ,Rule etc. 

 19) उत्तरातील महत्त्वाच्या शब्दांना key words अधोरेखित करावे. 

Numerical problems मध्ये Answer लिहिताना उत्तरास अधोरेखित ( underline) करावे अथवा box करावा.

20] Section B मध्ये कमीत कमी 2 small derivations 2 Marks चे आणि C मध्ये 2 ते 3 big derivations 3 Marks चे विचारले जातील असे गृहीत धरा.   Derivations मध्ये diagram , Explanation,  final formula / Equation याचे प्रत्येकी ½ marks हमखास मिळतात. ( एखाद्या विद्यार्थ्याला संपूर्ण derivation येत नसेल तर त्याने अशा पद्धतीने लिहिले तरी 1½ marks मिळतात.)

21] Numerical problems मध्ये Formula लिहून substitution केले तरी त्याचे Marking Scheme प्रमाणे प्रत्येकी ½ गुण मिळतात.  Numerical problem संपूर्ण सोडवल्यास त्या मध्ये सर्वच्या सर्व गुण मिळवता येतात.

22] Distinguish between....... या प्रकारचा प्रश्न सोडविताना tabular form मध्ये लिहावा. दोन्ही रकान्यात (column मध्ये) same parameter (मुद्द्या) संदर्भात फरक लिहावा. दोन्हीकडे मुद्दे बरोबर असतील तरच संपूर्ण एक मार्क मिळेल. ½ मार्क देण्याची त्यात तशी provision (marking scheme) नाही. 

23] a) Diagrams 1 or 2 Marks साठी विचारले असतील तर Correct Diagram साठी १/२ किंवा १ मार्क आणि 4 Labelling  करिता राहिलेला १/२ किंवा १ मार्क.

b) Ray diagram मध्ये direction (arrow) correct दाखवणे आवश्यक आहे. तसेच Brewster's law ची diagram असेल तर angle between Reflected Ray and Refracted Ray 90° असलाच पाहिजे. 

c) काही diagram मध्ये rectangular components of vector असतात. Vector F चे components F cosθ and F sinθ यामधील angle exact 90° असला पाहिजे.

d) Circuit diagram मध्ये direction of the current arrow ने correct दाखवला पाहिजे. शिवाय cell (battery) असेल  battery symbol च्या terminals ला + ve व - ve  sign दाखवा.

अत्यंत महत्वाचे:

24] उत्तर पत्रिकेचे Main Page काळजीपूर्वक हाताळावे.

उत्तरपत्रिकेत प्रश्न लिहू नयेत. प्रश्नाच्या उत्तराला संबंधित Title द्यावे.

Section A मध्ये, MCQs ची उत्तर लिहिताना एका ओळीला १ च लिहावे. नंतर १ ओळ सोडून पुढील MCQ चे उत्तर लिहावे. तसेच VSA मध्ये प्रत्येक उपप्रश्न झाले की १ ओळ सोडावी. 

प्रत्येक Section ची सुरुवात नवीन पेजवर करावी. तसेच Section  B, C, व D मध्ये प्रत्येक उपप्रश्न झाला कि एक ओळ सोडून  पुढील उपप्रश्न सुरू करावा. 

प्रत्येक section मधील निवडलेले उपप्रश्न सलग लिहावेत. शक्यतो दोन section मधील उपप्रश्न एकमेकात Mix करू नयेत. अगदीच नाईलाज झाला तर सर्वात शेवटी असे राहिलेले उपप्रश्न Section, Question No, Sub question No आणि Title सह लिहावेत.

25] Numerical Problems सोडवताना Log Table आवश्यकता असेल तर तो वेळेच्या आधी (Advance मध्ये) मागून घ्यावा. त्याचप्रमाणे Main उत्तर पत्रिका लिहून संपायला येण्याच्या आधीच Supplement मागून घ्यावी.

### ALL THE BEST ###