Class 12 Physics Important Question Answer solution with pdf. Here We Provides Class 1 to 12 all Subjects NCERT Solution with Notes, Question Answer, CBSE and HBSE Important Questions, MCQ and old Question Papers for Students.
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HBSE ( Haryana Board ) Solution of Class 12 Physics important Question And Answer solution for 2024 exams.
HBSE Class 12 Physics Important Questions 2024
HBSE Class 12 Physics Chapter 1 Electric Charges and Fields Important Questions 2024
Q1. Define the term electric dipole moment. Is it scalar or vector ?
Q2. What are electric field lines? Draw these for a point charge -Q. Most Important
Q3. State any two important properties of electrostatic field lines.
Q4. Two electrostatic field lines never cross each other. Why?
Q5. Define Electric flux. Is it a scalar or a vector quantity. Use Gauss’s law to derive the expression for the electric field 
due to a straight uniformly charged infinite line of charge density λ c/m.
Q6. What is electric flux ? State Gauss’s law for electric flux. Write important points regarding this law. Most Important
Q7. What is electric flux ? State Gauss’s law for electric flux. Write important points regarding this law.
Q8. State and prove Gauss’s Law in Electrostatics. Most Most Important
Q9. Obtain an expression for the Intensity of Electric field near a uniformly charged straight wire of Infinite Length, with the help of Gauss’s theorem in Electrostatics.
Q10. What is Coulomb’s law ? Write its expression. Most Important
Q11. Find the expression for electric field intensity E due to uniformly charged spherical shell at a point inside the shell.
Q12. Find the expression for electric field intensity E due to a uniformly charged thin spherical shell at a point outside the shell.
Q13. Find the expression for electric field intensity E due to a uniformly charged thin spherical shell at a point inside the shell.
Q14. Derive an expression for electric field intensity E near a thin uniformly charged infinite plane sheet.
Q15. Deduce expression for electric field intensity due to a uniformly charged thin spherical shell at a point inside the shell.
Q16. Determine electric field intensity near an infinitely long straight uniformly charged wire.
Q17. The force of attraction between a positively charged particle and a negatively charged particle is F. When distance between them is made one fourth, what will be the value of this force ?
Q18. The force of repulsion between two positively charged particles is F. When distance between them is made one fourth, what will be the value of this force ?
Q19. Quantization of charge was experimentally demonstrated by ________ in 1912.
Ans. Millikan
Q20. Electric field lines start from ________ and end at negative charges.
Ans. positive charges
Q21. The electric field due to an electric dipole is ________ symmetric.
Q22. The distance between two charged particles is halved. What will be the effect on the force between them?
Q23. The force of repulsion between two negatively charged particles is F. When distance between them is halved, what will be the value of this force ?
Q24. There are about ________ electrons in a charge of -1 coulomb.
HBSE Class 12 Physics Chapter 2 Electrostatic Potential and Capacitance Important Questions 2024
Q1. What is Electrostatic Potential ? Write its unit.
Q2. Derive relation between electric field E and potential V at a point.
Q3. What are equipotential surfaces ? Draw an equipotential surface due to point charge.
Q4. What is a capacitor? Derive an expression for the capacitance of a parallel plate capacitor in which a dielectric medium of dielectric constant K partially fills the space between the plates. Draw the necessary diagram.
Q5. Write expression for capacitance of a parallel plate capacitor and explain the effect of dielectrics on capacitance.
Q6. Three capacitors of capacitances 2 pF, 3 pF and 4 pF are connected in parallel. Determine the charge on each capacitor, if the combination is connected to a 100 V supply ? Most Important
Q7. Write expression for capacitance of three capacitors in series and parallel combinations.
Q8. Write the expression for energy density of electric field ‘E’ in free space.
Q9. Volt is unit of ________
Ans. potential difference.
Q10. The fall of potential per unit length of wire is called ________
Q11. A Electrostatic force between two point charges in vacuum is F. If the charge are kept at the same distance in water (Dielectric constant K = 80), then the force between them will be ________
Q12. Write the expression for energy stored in a capacitor in terms of charge and potential difference between its plates. Most Important
Q13. Write the expression for energy stored in a capacitor in terms of charge and capacitance?
Q14. Capacity can be increased by connecting different capacitors in ________
Q15. Average power consumed/cycle in an ideal capacitor is ________ .
Q16. On which factors does the capacitance of a capacitor depend?
Q17. Electric field is in the direction in which the ________ decreases steepest.
Ans. potential
Q18. An ________ surface is a surface with a constant value of potential at all points on the surface.
Ans. Equipotential
Q19. Write SI Unit of electrical energy.
Q20. Calculate the capacitance of the capacitor C in diagram. The equivalent capacitance of the combination between P and Q is 30 µF.
Q21. Calculate the equivalent capacitance between the points A and B in the 10 F following Figure :
Q22. What is capacitance of a capacitor? Calculate equivalent capacitance between points A and B :
Q23. Define capacitance and calculate equivalent capacitance between points A and B :
HBSE Class 12 Physics Chapter 3 Current Electricity Important Questions 2024
Q1. State Kirchhoff’s Laws for electrical circuits giving necessary circuit diagram.
Q2. Explain Kirchhoff’s Junction rule. Most Important
Q3. What is Kirchhoff’s loop rule ? Most Important
Q4. Explain the Kirchhoff’s voltage law.
Q5. What do you mean by eddy currents? How it can be produced. Write the name of applications of eddy currents.
Q6. State Wheatstone bridge principle and deduce it using Kirchhoff’s rules.
Q7. Draw circuit diagram of a wheatstone bridge and write the expression for the balance condition.
Q8. Define a Wheatstone bridge ? Draw labelled diagram and discuss the balance condition.
Q9. Draw the circuit diagram of a Wheatstone bridge. Derive its balance condition to give null deflection in galvanometer.
Q10. Name the practical device based on the principle of Wheatstone bridge. Determine the value of unknown resistance by this device.
Q11. Draw the circuit diagram for Wheatstone bridge to determine unknown resistance. Write condition for balancing of the bridge.
Q12. Explain Wheatstone bridge with the help of a diagram.
Q13. What is Ohm’s law ? Write its relation. Most Important
Q14. Write any two limitations of Ohm’s Law ?
Q15. Write any two conditions when Ohm’s Law fails?
Q16. Explain the use of meter bridge for finding an unknown resistance. Most Important
Q17. Draw the circuit diagram to determine unknown resistance using metrebridge. Write the equation for determining the unknown resistance. Most Important
Q18. Write the relation between resistance and resistivity of a conductor. Which of these quantities does not change for same material?
Q19. An important quantity is the mobility μ defined as the magnitude of the ________ per unit electric field.
Ans. Drift velocity .
Q20. Two unequal resistance are connected in parallel. What is same for them? Most Important
Q21. What is the effect on resistivity in metals, with increase in temperature?
Q22. Write SI unit of resistivity of a semiconductor.
Q23. Write SI unit of resistivity of a metal.
Q24. Write down the formula for the relation of current density (J) specific conductivity (σ) and the electric field (E).
Q25. Write down the formula for the relation of current density (J) and drift velocity (Vd).
Q26. Write relation between Electromotive force and terminal potential difference for a cell.
Q27. The unit of Resistance is ________ .
Q28. ________ is a device can be used to measure potential difference, internal resistance of cell and compare emf’s of two cells.
Q29. Under what condition, is terminal voltage of a cell equal to its Electromotive Force ?
Q30. Are Kirchhoff’s rules applicable to both a. c. and d. c. ?
Q31. ________ is the SI unit of conductivity.
Q32. Current density is scalar quantity or vector quantity.
Q33. Electric wiring in our homes has three wires : live, neutral and ________
Q34. What is the effect on relaxation time of electrons in metals, with increase in temperature.
Q35. What is the effect on relaxation time of electrons in metals, with decrease in temperature?
Q36. The conductance of a wire of resistance 2 µΩ is ________ .
Q37. Conductivity arises from mobile charge carriers. In metals, these mobile charge carriers are ________ .
Q38. The electrolyte through which current flows has a finite resistance, called the ________ .
Ans. internal resistance.
Q39. Current through a given area of a conductor is the net ________ passing per unit time through the area.
Ans. Charge
Q40. What is the maximum current that can be drawn from a storage battery of emf 10 V and internal resistance 0.2Ω ? Most Important
Q41. The maximum current that can be drawn from a storage battery of emf 18 V is 30 A. What is its internal resistance ? Most Important
Q42. Write SI Unit of electrical power.
Q43. How much current flows through a 3 kΩ resistor when a potential difference of 9 V is applied across its ends? Most Important
Q44. Define resistance of a conductor and calculate equivalent resistance between points X and Y :
Q45. Calculate the equivalent resistance between the points A and B in the given Figure.
HBSE Class 12 Physics Chapter 4 – Moving Charges and Magnetism Important Questions 2024
Q1. State Biot-Savart’s Law and write its Mathematical form. Most Important
Q2. Using Biot-Savart’s law derive an expression for the magnetic field at the centre of a current carrying circular loop.
Q3. A circuit Loop of radius R carries a current I. Obtain an expression for the magnetic field at a point on its axis at a distance X from its centre.
Q4. Explain the principle and working of a Cyclotron. Most Important
Q5. Explain the principle and working of a cyclotron using its schematic sketch. Show that time of revolution of an ion is independent of its speed or radius of its orbit. Most Important
Q6. Explain the working of a cyclotron with diagram. What type of particles can be accelerated using it? Most Important
Q7. Explain the principle of a moving coil galvanometer. How can it be converted into a voltmeter? Explain with the help of diagram. Most Important
Q8. A Explain the principle of a moving coil Galvanometer. How can it be converted into an ammeter ? Draw necessary diagram. Most Important
Q9. Define current sensitivity and voltage sensitivity of a moving coil galvanometer. How can a galvanometer be made more sensitive?
Q10. Explain the principle and working of a moving coil galvanometer with the help of a labelled diagram.
Q11. Explain the principle of a moving coil galvanometer. How can it be converted into an ammeter ?
Q12. What is a Solenoid? How much magnetic field is due to a long solenoid? How its direction is determined ?
Q13. Define ampere circuital law? Write expression for magnetic field at a distance r from a straight infinite wire carrying current I. Which rule is used to determine the direction of this magnetic field?
Q14. Using Ampere’s law find an expression for the magnetic field due to a straight long current carrying wire at a distance r outside it.
Q15. Derive an expression for the magnetic field at the centre of a circular current carrying loop.
Q16. Find expression for magnetic field due to straight infinite current carrying wire at a distance r outside it.
Q17. The value of magnetic field at any point in the open space inside the toroid is ________ .
Q18. The ________ inside solenoid becomes everywhere parallel to the axis.
Q19. Tesla is the unit of ________ .
Q20. Can we decrease the range of a given ammeter ?
Q21. According to ________ rule, your extended thumb pointing in the direction of the current. Your fingers will curl around in the direction of the magnetic field.
Q22. Write SI unit of magnetic field.
Q23. Consider the circuit shown where APB and AQB are parts of square. What will be the Magnetic field at the centre O of the square
.
Q24. Consider the circuit shown where APB and AQB are semicircles. What will be the magnetic field at the centre O of the circle ?
.
HBSE Class 12 Physics Chapter 5 Magnetism and Matter Important Questions 2024
Q1. Define the term magnetic permeability μ and write its unit.
Q2. Define the term magnetic susceptibility χm and write its unit.
Q3. Define the term magnetization M and write its unit.
Q4. Explain Domain theory of ferromagnetism. How ferromagnetism depends upon temperature?
Q5. Define the term angle of dip and declination.
Q6. Define different types of magnetic materials and give one example in each case.
Q7. Define the term magnetic intensity H and write its unit.
Q8. What is the value of magnetic permeability of a perfectly diamagnetic substance? Most Important
Q9. What is the value of magnetic susceptibility of a perfectly diamagnetic substance?
Q10. The horizontal and vertical components of the earth’s magnetic field at a place are equal. What is angle of dip at the place.
Q11. Three quantities are needed to specify the magnetic field of the Earth on its Surface-the horizontal component, the magnetic declination and ……… .
Q12. What is the value of angle of dip at the Earth’s magnetic poles? Most Important
Q13. Write SI Unit of magnetic intensity.
Q14. What is the relative magnetic permeability of a substance whose magnetic susceptibility is – 1 ?
HBSE Class 12 Physics Chapter 6 Electromagnetic Induction Important Questions 2024
Q1. What is electromagnetic induction? Explain.
Q2. What is magnetic flux ? Write its SI unit. Explain its relation with magnetic field lines using a diagram.
Q3. Explain the principle and working of A. C. Generator. Most Important
Q4. Define self and mutual inductance.. Most Important
Q5. Calculate self-inductance of a coil when current in it changes by 2A in 10-2 seconds and emf produced in 20 volts.
Q6. Define self-induction and the coefficient of self-inductance. Most Important
Q7. Calculate the self-inductance of a coil when 10 V induced emf is produced in it due to change in current at the rate of 80 A/s.
Q8. Calculate the emf (electromotive force) induced in a coil of self- inductance 10-2 H, when current in it changes at the rate of 20A per second.
Q9. What is mutual induction? Define its coefficient.
Q10. Calculate the mutual inductance of a coil when 10 V induced emf is produced in it due to change in current at the rate of 50 A/s in the neighbouring coil.
Q11. State Faraday’s law of electromagnetic induction and mathematical form. Most Important
Q12. State Lenz’s law. Most Important
Q13. What is Lenz’s law for electromagnetic induction? Most Important
Q14. If ω is angular frequency of a. c., then the reactance offered by Inductance L and Capacitance C are XL = ________ and XC = ________ .
Q15. SI unit of self-inductance is ________ .
Q16. SI unit of coefficient of mutual inductance is ________ .
Q17. The magnetic flux passing through a ring is increased from φ1 to φ2 at a constant rate in time t. The value of Induced Electromotive force will be ________.
Q18. Write SI Unit of magnetic flux.
Q19. Write SI Unit of magnetic flux density.
Q20. In an ac generator, mechanical Energy is converted to ________ .
Q21. An a. c. generator is based on the phenomenon of ________ .
Q22. The generation of emf by a solar cell, when light falls on, it is due to the following three basic processes : generation, separation and ________ .
Q23. When a metal rod of length I is placed normal to a uniform magnetic field B and moved with a velocity v perpendicular to the field, the induced emf (called motional emf) across its end is ________ .
Q24. The induced emf can be increased by ________ the number of turns (N) of a closed coil.
Ans. increasing
HBSE Class 12 Physics Chapter 7 Alternating Current Important Questions 2024
Q1. Explain sharpness of resonance in a series LCR circuit. Define its quality factor Q and write expression for it.
Q2. Obtain the resonant frequency ωo of a series LCR circuit with L = 2.0 H, C = 32 μF and R= 10 Ω.
Q3. Define resonance in LCR circuit. Find Power factor of series resonance LCR circuit.
Q4. Explain the phenomenon of resonance in series LCR circuit. frequency.
Q5. A series LCR circuit with R = 40Ω, L = 8H and C = 50 μF is connected to a variable frequency 240 V ac supply. Most Important (a) What is the angular frequency ω0 of the source at which resonance occurs? (b) Calculate the impedance and current at resonant condition.
Q6. Explain the principle and working of a step-down transformer using a diagram.
Q7. Describe briefly with the help of a labelled diagram, principle of step-up Transformer.
Q8. What is Transformer ? Draw its labelled diagram.
Q9. Explain the principle and working of a transformer. Most Important
Q10. What are Eddy currents? Explain. Most Important
Q11. What are Eddy currents? Write any two applications of Eddy currents.
Q12. Name four applications of Eddy currents.
Q13. What are magnetic elements at a place ? Define any one.
Q14. A 100 Hz (hertz) a. c. is flowing in a 14 mH coil. Find its Reactance.
Q15. What is Inductive reactance ? How it is related to capacitive reactance at resonance?
Q16. What is capacitive reactance? How it is related to inductive reactance at resonance ?
Q17. A series L-C-R circuit with R = 44Ω, C = 8μF and L= 50 H is connected to a variable frequency 220 V ac supply. Calculate angular frequency, impedance and current at resonance condition. Most Important
Q18. What e. m.f. will be induced in a 10 H inductor in which current changes from 10 A to 7A in 9 x 10-2s ?
Q19. A resistor of 12 ohm, a capacitor of reactance 14 ohm and an inductor of reactance 30 ohm are joined in series and placed across a 230 v, 50Hz supply. Calculate : (i) Impedance and (ii) Current in the circuit
Q20. A 80 mH inductor and a 60 μF capacitor are connected to a 230 V, 50 Hz supply. If the rms current in the circuit is Irms = 8.24 A, calculate the rms value of potential drop across each element.
Q21. A resistor of 200Ω and a capacitor of 15.0 μF are connected in series to a 220 V, 50 Hz ac supply. If the current in the circuit is Irms = 0.755 A, calculate the voltage across element.
Q22. A 100 μF capacitor and a resistance of 40Ω are connected to a 110 V, 60Hz ac supply in series. If the rms current in the circuit is Irms = 2.28 A, calculate the rms value of potential drop across each element.
Q23. A coil of inductance 0.5 H and a resistance of 100 Ω are connected to a 240 V 50Hz ac supply in series. If the rms current in the circuit is Irms = 1.29 A, calculate the rms value of potential drop across each element.
Q24. Derive an expression for the force between two parallel straight conductors carrying currents in the same direction. Hence define one ampere. Most Most Important
Q25. Derive an expression for the force between two Long straight parallel conductors carrying current in opposite direction. Hence define one Ampere.
Q26. Explain the magnetic hysteresis loop? What are its uses?
Q27. What is the value of power factor of a purely resistive ac circuit?
Q28. What is the value of power factor of a purely capacitive ac circuit ?
Q29. The power factor of an a. c. circuit is given by cosΦ = ________ .
Q30. What are iron loss in a Transformer ?
Q31. An inductor acts as a conductor for d. c., why?
Q32. The peak value of 220 V a. c. is c .
Q33. How much power is dissipated in a purely inductive ac circuit ?
HBSE Class 12 Physics Chapter 8 Electromagnetic Waves Important Questions 2024
Q1. Write two uses each of Microwaves and Gamma rays. Most Important
Q2. Write two uses each of Radio waves and X-rays. Most Important
Q3. Write two uses of UV-rays and X-rays. 2
Q4. What are electromagnetic waves ?
Q5. Write any two important features of electric field E and magnetic field B of an electromagnetic wave.
Q6. Define displacement current and write its mathematical form. Most Important
Q7. The electric field in a plane electromagnetic wave is : Ex = 3.1cos(1.8×10-2 y + 5.4×106 t) Newton/Coulomb. What is the wavelength and frequency of the wave? Most Important
Q8. Which electromagnetic wave are used in cellular phones to transmit voice communication in the Ultra High Frequency (UHF) band ?
Q9. Which electromagnetic radiation is used in medicine to destroy cancer cells ?
Q10. X-rays γ-rays and radiowaves are propagating in vacuum, there will be same ________ but frequencies will be different.
Q11. The electromagnetic waves of frequency range from 5 x 105 Hz to 109 Hz are called ________ .
Q12. The velocity of electromagnetic waves in free space can be given by the relation ________ .
Q13. ________ (physical quantity) is same for X-rays of wavelength 10-10 m, red light of wavelength 6800Å and radio waves of wavelength 500 m.
Q14. If E and B represents electric field and magnetic field vectors of the electromagnetic wave, the direction of propagation of electromagnetic wave is along : 
Q15. One common way to generate ________ rays is to bombard a metal target by high energy electrons.
Ans. X
Q16. Which electromagnetic wave is used to kill germs in water purifiers ?
Ans. Ultraviolet rays
Q17. Which electromagnetic wave is used in remote switches of TV sets?
Q18. A charged particle oscillates about its mean equilibrium position with a frequency of 109 Hz. The frequency of the electromagnetic waves produced by the oscillator is ________ .
Q19. ________ waves are produced by hot bodies and molecules.
Ans. Infrared
HBSE Class 12 Physics Chapter 9 Ray Optics and Optical Instruments Important Questions 2024
Q1. Define Total Internal Reflection.
Q2. Define power of a lens and give its SI unit.
Q3. Define power of a lens and give its relation with focal length. Most Important
Q4. Define focal length and power of a lens.
Q5. Draw a labelled ray diagram showing image formation in an astronomical telescope. Derive expression for its magnifying power. Most Most Important
Q6. Draw ray diagram of an astronomical telescope and define its magnification. Most Important
Q7. Draw a labelled ray diagram showing the formation of image in a compound microscope. Define its magnifying power and write expression for it. Most Most Important
Q8. Draw the ray diagram of a compound microscope and obtain an expression for the magnifying power of microscope, when final image is formed at the least distance of distinct vision. Most Important
Q9. Draw the ray diagram of a compound microscope and define its magnification.
Q10. A tank is filled with water to a height of 12.5 cm. The apparent depth of a needle Lying at the bottom of the tank is measured by microscope to be 9.4 cm. What is the refractive Index of water ?
Q11. Draw the ray diagram of a simple microscope. Write expression for its magnification. 3
Q12. What is speed of light in vacuum?
Q13. Monochromatic light is refracted from air into a medium of refractive index n. What is the ratio of the wavelengths of the incident and the refracted waves. Most Important
Q14. Two thin Lenses of power +5 dioptre and -5 dioptre are placed in contact. Find the power of this Combination.
Q15. A point source of light is placed at a distance of 40 cm from a convex lens of focal length 20 cm. Where should image formed on the other side of lens.
Q16. An object is placed at a distance of 2 F from a convex lens of focal length F. Where should image of object formed on the other side of lens.
Q17. Two thin lenses of power +5 Dioptre and -3 Dioptre are placed in contact. Find the power of this combination.
Q18. The power of a lens is + 5D. Write the focal length.
Q19. The relation between angle of incidence i, angle of prism A and angle of minimum deviation for a triangular prism is ________ .
Q20. The ________ angle for a ray incident from a denser to rarer medium, is that angle for which the angle of refraction is 90°.
Q21. For total internal reflection, light must travel to ________ to ________ .
Q22. Snell experimentally obtained the laws of ________ of light.
Ans. refraction
Q23. The ratio of the sine of the angle of incidence to the sine of angle of refraction is ________ .
Ans. constant.
Q24. What is a transducer ?
HBSE Class 12 Physics Chapter 10 Wave optics Important Questions 2024
Q1. What is diffraction of light? Explain the intensity distribution graph due to diffraction from a single slit. Most Important
Q2. Using Huygen’s construction, explain reflection of a plane wave by a plane surface. Most Important
Q3. State Huygens principle and prove the law of reflection on the basis of wave theory.
Q4. Write Huygen’s principle of secondary wavelets, and use it to explain law of reflection of light.
Q5. What is wavefront? Using Huygen’s principle to verify the Laws of reflection.
Q6. Define wavefront. State Huygen’s principle. Using Huygen’s construction show propagation of a plane wavefront.
Q7. Define wavefront. State Huygen’s principle. Using Huygen’s construction show propagation of a spherical wavefront.
Q8. Find out the expression for Fringe width in Young’s double slit experiment. Most Important
Q9. In Young’s double-slit experiment the distance between the central bright fringe and the fourth bright fringe is measured to be 1.2 cm. Determine the wavelength of the light used if the slits are separated by 0.28 mm and the screen is placed 1.4 m away. Most Important
Q10. In Young’s Double slit experiment, deduce the conditions for obtaining constructive and destructive interference fringes.
Q11. Draw : (i) schematic diagram, (ii) fringe pattern, and (iii) intensity distribution graph for Young’s double slit interference experiment.
Q12. What is interference of light waves? State two essential conditions to observe it.
Q13. What is interference? What are basic requirements for a sustained interference pattern?
Q14. In Young’s double-slit experiment, the slits are separated by 0.28 mm and the screen is placed 1.4 m away. Calculate the fringe separation for light of wavelength 600 nm.
Q15. What is polarization of light? Briefly describe polarization by reflection and polarization by scattering of light ? Most Important
Q16. What is polarization of light? Calculate the refractive index of a medium if angle of polarization is 60°
Q17. Explain polarization of light by reflection with a diagram. Define angle of polarization.
Q18. Define polarization of light. Calculate the angle of polarization for medium having refractive index √3.
Q19. Explain polarization by reflection of light. Calculate the refractive index of a medium if angle of polarization is 60°.
Q20. What are coherent sources of light? Derive mathematically the conditions for constructive and destructive interference at an arbitrary point due to two coherent sources in terms of phase difference φ. Most Important
Q21. What is interference of light waves? Write formula of fringe width.
Q22. In a single slit diffraction experiment, the width of the slit is made double the original width. How does this affect the size of central diffraction band?
Q23. If the Young’s apparatus be immersed in water in place of air, then what will be the effect on the Fringe width?
Q24. In Young’s experiment what will be the effect on fringe-width on using yellow colour light of sodium Lamp in place of violet colour light?
Q25. What is shape of a wavefront around a straight line source?
Q26. Is the speed of light in glass independent of the colour of light? (Yes or No) Most Important
Ans. No
Q27. What is the shape of portion of wavefront of light from a distant star intercepted by earth?
Q28. For which spectral colour of Light is the speed Maximum in glass?
Q29. Two light waves of equal amplitude and wavelength are superimposed. What is the phase difference between the waves so that amplitude of the resultant wave will be maximum.
HBSE Class 12 Physics Chapter 11 Dual Nature of Radiations and Matter Important Questions 2024
Q1. Using Einstein’s photoelectric equation, explain effect of frequency incident radiation on stopping potential. Most Important
Q2. Write Einstein’s photoelectric equation. Define the threshold frequency v0 and stopping potential V0.
Q3. Write Einstein’s Photoelectric Equation. Draw a graph between the stopping potential and Frequency of the Incident light.
Q4. Describe the variation of stopping potential with frequency of incident radiation for a given photosensitive material.
Q5. Define photoelectric emission and write Einstein’s photoelectric equation.
Q6. Write two laws of photoelectric emission.
Q7. What is photoelectric emission? Define threshold frequency for it.
Q8. If the work function of Caesium is 2.14 eV then find its threshold frequency. Most Important
Q9. What is photoelectric effect? Explain effect of intensity on photoelectric current. Most Important
Q10. Explain effect of potential on photoelectric current. Most Important
Q11. Discuss the variation of photoelectric current with collector plate potential for different frequency of incident radiation.
Q12. What is photoelectric effect? Explain variation of photoelectric current with applied potential.
Q13. What is a photon ? Write its important properties.
Q14. Find the energy of monochromatic light each beam photon in of wavelength 632.8nm.
Q15. Discuss the variation of photocurrent with collector plate potential for different intensity of radiation.
Q16. Which phenomenon illustrates the nature of light waves ?
Q17. Name any one effect of light which does not show its particle nature.
Q18. Why are alkali metal surfaces most suited as photo-sensitive surfaces?
Q19. The minimum energy needed by an electron to come out from a metal surface is called the ________ of the metal.
Q20. Photons are electrically ________ .
Ans. neutral.
HBSE Class 12 Physics Chapter 12 Atoms Important Questions 2024
Q1. Calculate the energy equivalent of 1.6 gram of a substance first in Joules and then in MeV. Most Important
Q2. What is de Broglie wavelength of a bullet of mass 0.040 kg travelling at a speed of 1.0km / sec ?
Q3. What is the de Broglie wavelength of a dust particle of mass 1.0 x 10-9 kg drifting with a speed of 2.2 m/sec ?
Q4. How de Broglie hypothesis provides an explanation for Bohr’s second postulate of quantization of angular momentum ?
Q5. What is de Broglie wavelength of a bullet of mass 0.050 kg travelling at a speed of 2.0 km/sec ?
Q6. Discuss the three postulates of Bohr’s model for hydrogen atom. Most Important
Q7. Draw the energy Level diagram for hydrogen atom and show transitions corresponding to Lines of Lyman and Balmer Series. Most Important
Q8. The ground state energy of hydrogen atom is -13.6 eV. Find the kinetic energy and the potential energy of the electron in this state. Most Important
Q9. The radius of the first electron-orbit in hydrogen atom of Bohr model is ro What will be the radius of the third orbit.
Q10. The mass of an electron is m and has charge e. If this electron is accelerated by a potential difference of V, then write the formula for the de-Broglie wavelength associated with it.
Q11. A particle of mass m is moving with a velocity v. Write down the formula for the de-Broglie wavelength associated with the particle.
Q12. The mass of a charged particle is m and has charge q. If this particle is accelerated by a potential difference of V, then write the formula for the de-Broglie wavelength Associated with it.
Q13. In Rutherford’s nuclear model of the atom, the entire positive charge and most of the mass of the atom are concentrated in the …….. .
Q14. In Rutherford’s model, most of the mass of the atom and all its positive charge are concentrated in a tiny nucleus and the ………. revolved around it.
Q15. Photons are not deflected by Electric and ________ fields.
Ans. magnetic
Q16. ________ as a whole, is electrically neutral and therefore contains equal amount of positive and negative charges.
Ans. Atom
HBSE Class 12 Physics Chapter 13 Nuclei Important Questions 2024
Q1. Draw a graph between potential energy of a pair of nucleons and separation between them. Also write its main features.
Q2. What is nuclear fusion ? Write its one example and one use of this reaction. Most Important
Q3. Derive equation for radioactive decay using laws of radioactivity and define decay constant..
Q4. Explain nuclear fission and nuclear fusion and give their uses. Most Important
Q5. Define nuclear fission. Write the fission reactions of a neutron with Uranium isotope 
. Write one use of nuclear fission reaction.
Q6. What are the functions of the control rods and the moderators? Explain Nuclear Fission with example.
Q7. What is Nuclear fission ? Write one example.
Q8. Define mass defect and nuclear binding energy. For a nucleus 
, write the value of mass defect and nuclear binding energy. Most Important
Q9. What do you mean by mass defect of nucleus ? How mass defect related to binding energy of nucleus ?
Q10. Draw binding energy curve and discuss its two main features.
Q11. Write the relation between kinetic energy of a-particle and its distance of closest approach
Q12. Write the relation between kinetic energy of α-Particle and its distance of closest approach from nucleus in Rutherford’s a-scattering experiment.
Q13. What is basic nuclear process underlying ẞ– decay? Write nuclear reaction of this decay for 
.
Q14. A Define the term Half-life period and decay constant of a radioactive element. Write the relation between them. Most Important
Q15. Define decay constant and half life and derive a relation between them.
Q16. Explain the laws of radioactive decay. Derive an equation of radioactive decay using these laws. Most Important
Q17. Derive equation of radioactivity using laws of radioactive decay. Define half life period.
Q18. Derive the relation N (t) = N0e-λt for radioactive decay. Sketch a graph of this relation. Show half life time (T1/2) in this graph.
Q19. What is basic nuclear process underlying B+ decay? Write nuclear reaction of this decay for 
. Most Important
Q20. What is basic nuclear process underlying B– decay? Write nuclear reaction equation of this decay for 
.
Q21. What is basic nuclear process underlying B+ decay? Write nuclear reaction equation of this decay for 
.
Q22. State the law of radioactive decay. Derive an expression showing the variation of number of undecayed nuclei with time.
Q23. Define decay constant and half-life and derive a relation between them.
Q24. Write the relation between kinetic energy of a-particle and its distance of closest approach from nucleus in Rutherford’s a-scattering experiment.
Q25. Who discovered neutron ?
Q26. In ________ , heavy nucleus decays into lighter nucleus.
Q27. Isotones are the nuclides which contain ________ .
Q28. In ________ lighter nuclei combine to form a larger nucleus.
Q29. Two nuclei have mass numbers in the ratio 1 : 27. What is the ratio of nuclear density.
Q30. Calculate the ratio of the radii of two nuclei of mass numbers 1 and 27 respectively.
Q31. Write the relation between radius R and mass number A of a nucleus.
Q32. 1 Decay per second are equivalent to what unit of radioactivity?
Q33. Who discovered radioactivity?
Q34. Energy of photon having frequency v is ________ .
Q35. The energy of photon of wavelength λ is ________ .
Q36. What is SI unit of activity of radioactive substance?
Q37. How much activity is one Becquerel (1 Bq) ? Most important
HBSE Class 12 Physics Chapter 14 Semiconductor Electronics : Materials, Devices and Simple Circuits Important Questions 2024
Q1. What is doping? State two differences between N-type and P-type.
Q2. What are P-type semiconductors ? How they are formed ?
Q3. What are N-type semiconductors ? How they are formed ? Most Important
Q4. What is the difference between P and N-type semiconductors ?
Q5. Explain the use of P-N diode as full wave rectifier.
Q6. Explain the use of P-N diode as half-wave rectifier.
Q7. Write the names of two important processes formation of p-n Junction. Define the depletion region and potential barrier in it.
Q8. Two important process occur during the formation of a p-n junction: diffusion and ________ .
Q9. In an n-type silicon ________ are minority carriers.
Q10. The number of charge carriers can be changed by ‘doping of a suitable impurity in pure semiconductors. Such semiconductors are known as ________ semiconductors.
Q11. In a semiconductor, the concentration of electrons is 8×1013 cm-3 and that of holes is 5×1012 cm-3. Is it a p-type or n-type semiconductor ?
Q12. In intrinsic semiconductors, what is the ratio of the number of free electrons (ne) to the number of holes (nh).
Q13. The number of electrons (ne) is equal to the number of holes (nn) in ________ Semi conductors..
Ans. Intrinsic
Q14. In a semiconductor, the concentration of electrons is 5 x 1012 cm-3 and that of holes is 8×1013 cm-3. Is it a p-type or n-type semiconductor ?
Q15. Draw the circuit diagram of Half wave rectifier, showing input and output waves.
Q16. Draw a circuit diagram of full-wave rectifier. Explain its working principle. Draw the input/output wave forms indicating clearly the function of two diodes used.
Q17. Draw the circuit diagram of a full wave rectifier using two p-n Junction diode. Draw input, output wave form also.
Q18. Draw the circuit diagram of a half-wave rectifier using two p-n Junction diode. Show wave forms of input and output voltages also. Most Important
Q19. Draw a circuit diagram of a full wave rectifier and explain its output waveform. Most Important
Q20. Draw the circuit diagram of an half wave rectifier and explain its output waveform.
Q21. Draw the circuit of full wave rectifier with capacitor filter. Also draw the input and output voltage of this circuit
Q22. Draw the circuit diagram of a half wave rectifier circuit and input and output waveforms of this rectifier
Q23. Is the Junction, diode D is forward or reverse biased in the given diagram?
Q24. Is the Junction diode D is forward or reverse biased in the given diagram?
Q25. Is the Junction diode D is forward or reverse biased, in the given diagram
