CBSE Class 12 Physics 2023
296 questions · 563 marks · every one with the board’s own marking-scheme answer.
What 2023 actually asked, chapter by chapter
Marks we counted in the 2023 papers themselves. CBSE allocates marks per unit, not per chapter — this is what was observed, not an official CBSE weightage.
| Chapter | Marks | Share |
|---|---|---|
| Ray Optics and Optical Instruments26 questions | 68 | 12.1% |
| Current Electricity38 questions | 67 | 11.9% |
| Moving Charges and Magnetism27 questions | 55 | 9.8% |
| Semiconductor Electronics: Materials, Devices and Simple Circuits29 questions | 46 | 8.2% |
| Electromagnetic Induction20 questions | 45 | 8.0% |
| Dual Nature of Radiation and Matter27 questions | 45 | 8.0% |
| Alternating Current19 questions | 43 | 7.6% |
| Electric Charges and Fields20 questions | 42 | 7.5% |
| Nuclei19 questions | 33 | 5.9% |
| Atoms18 questions | 32 | 5.7% |
| Wave Optics16 questions | 29 | 5.2% |
| Electromagnetic Waves17 questions | 25 | 4.4% |
| Electrostatic Potential and Capacitance10 questions | 21 | 3.7% |
| Magnetism and Matter10 questions | 12 | 2.1% |
All 296 questions from 2023
- Q1A charge Q is placed at the centre of a cube. The electric flux through one if its face is1 mk
- Q1The ratio of the magnitudes of the electric field and magnetic field of a plane electromagnetic wave is1 mk
- Q1An electric dipole of length 2 cm is placed at an angle of 30^° with an electric field 2 × 10^5 N / C. If the dipole…1 mkasked 2×
- Q1A battery of emf E and internal resistance r is connected to an external circuit. The potential drop within the battery…1 mk
- Q1An electron experiences a force (1 · 6 × 10^-16 N) i in an electric field E. The electric field E is:1 mk
- Q1The magnitude of the electric field due to a point charge object at a distance of 4.0 m is 9 N / C. From the same…1 mk
- Q1Two charges q 1 and q 2 are placed at the centres of two spherical conducting shells of radius r 1 and r 2…1 mk
- Q1Two identical circular coaxial coils A and B, arranged in vertical planes parallel to each other, carry currents in the…1 mk
- Q2A steady current flows through a metallic wire whose area of cross-section increases continuously from one end of the…1 mkasked 3×
- Q2The energy of a photon of wavelength 663 nm is1 mk
- Q2A point P lies at a distance x from the mid point of an electric dipole on its axis. The electric potential at point P…1 mk
- Q2An electron enters a uniform magnetic field with speed v. It describes a semicircular path and comes out of the field.…1 mk
- Q2The momentum of a photon of wavelength λ is:1 mk
- Q2Which one of the following is not a scalar quantity?1 mk
- Q2Specify the transition of electron in the wavelength of the line in the Bohr model of hydrogen atom which gives rise to…1 mk
- Q2A light of frequency v is incident on a metal surface whose work function is W 0. The kinetic energy of emitted…1 mk
- Q2For a metallic conductor, the correct representation of variation of resistance R with temperature T is:1 mk
- Q3Two thin long parallel wires A and B are separated by a distance r and carry current I each in the same direction. The…1 mk
- Q3The current density due to drift of electrons in a conductor is given by: (symbols have their usual meanings)1 mk
- Q3The minimum distance between an object and its real image formed by a convex lens of focal length f is:1 mk
- Q3Which of the following has its permeability less than that of free space?1 mkasked 2×
- Q3A current of 0.8 A flows in a conductor of 40 Ω for 1 minute. The heat produced in the conductor will be1 mk
- Q3The potential difference across a cell in an open circuit is 8 V. It falls to 4 V when a current of 4 A is drawn from…1 mk
- Q3An electromagnetic wave is produced by a charge1 mk
- Q3At a certain temperature in an intrinsic semiconductor, the electrons and holes concentration is 1.5 × 10^16 m^-3. When…1 mkasked 3×
- Q3The magnetic field lines near a substance are as shown in the figure. The substance is:1 mk
- Q3Which of the following cannot modify an external magnetic field as shown in the figure?1 mk
- Q4A particle of mass m and charge -q is moving with a uniform speed v in a circle of radius r, with another charge q at…1 mk
- Q4A cell of emf E is connected across an external resistance R. When current ' I ' is drawn from the cell, the potential…1 mkasked 3×
- Q4A square shaped coil of side 10 cm, having 100 turns is placed perpendicular to a magnetic field which is increasing at…1 mkasked 3×
- Q4The figure shows variation of current (I) with time ( t ) in four devices P, Q, R and S. The device in which an…1 mkasked 3×
- Q4An infinitely long uniformly charged wire produces an electric field of 18 × 10^4 NC^-1 at a distance of 1 · 0 cm. The…1 mk
- Q4A semiconductor device is connected in series with a battery, an ammeter and a resisitor. A current flows in the…1 mk
- Q4Two wires of equal length and radii r and 2 r are connected in series. Their resistivities are 2 ρ and ρ respectively.…1 mk
- Q5Beams of electrons and protons move parallel to each other in the same direction. They1 mkasked 2×
- Q5The electromagnetic waves used in radar systems are:1 mkasked 2×
- Q5A particle of mass m and charge q moving with a uniform velocity v=v 0 x i+v 0 y j enters a region with a magnetic…1 mk
- Q5Which one of the following electromagnetic radiation has the least wavelength?1 mkasked 2×
- Q5At 0 K, the resistivity of an intrinsic semiconductor is:1 mk
- Q5A capacitor is charged by a battery. Between the plates, during process of charging:1 mk
- Q5Choose the correct option related to wavelengths ( λ ) of different parts of electromagnetic spectrum.1 mk
- Q5An isolated point charge particle produces an electric field E at a point 3 m away from it. The distance of the point…1 mk
- Q5A diamagnetic substance is brought near the north or south pole of a bar magnet. It will be:1 mkasked 3×
- Q6An inductor, a capacitor and a resistor are connected in series across an ac source of voltage. If the frequency of the…1 mkasked 3×
- Q6In a Young's double-slit experiment, the fringe width is found to be β. If the entire apparatus is immersed in a liquid…1 mkasked 3×
- Q6The atomic number of an atom represents:1 mk
- Q6A long straight wire of radius 'a' carries a steady current ' I '. The current is uniformly distributed across its area…1 mkasked 2×
- Q6In a Young's double-slit experiment, the screen is moved away from the plane of the slits. What will be its effect on…1 mkasked 3×
- Q6A point charge q is kept at a distance r from an infinitely long straight wire with charge density λ. The magnitude of…1 mk
- Q6The radius of 13^27 X nucleus is R. The radius of 53^125 Y nucleus will be1 mk
- Q6Which one of the following has relative magnetic permeability between 0 and 1?1 mk
- Q6A circular coil of radius 8.0 cm and 40 turns is rotated about its vertical diameter with an angular speed of 25/(π)…1 mkasked 3×
- Q6In an experiment, photons of energy 7 · 5 eV are incident on a metal surface. Electrons emitted from the metal surface…1 mk
- Q7E and B represent the electric and the magnetic field of an electro- magnetic wave respectively. The direction of…1 mk
- Q7Photons of energy 3 · 2 eV are incident on a photosensitive surface. If the stopping potential for the emitted…1 mkasked 2×
- Q7Figure shows a rectangular conductor PSRQ in which movable arm PQ has a resistance ' r ' and resistance of PSRQ is…1 mk
- Q7E, c and v represent the energy, velocity and frequency of a photon. Which of the following represents its wavelength?1 mk
- Q7The electromagnetic radiations used to kill germs in water purifiers are called:1 mk
- Q7In an experiment on photoelectric effect, the intensity of incident radiation is increased, keeping the frequency v the…1 mk
- Q7The ratio of the magnitude of magnetic moment to that of angular momentum, of an electron revolving around the nucleus…1 mk
- Q7The energy of a photon of wavelength λ is1 mkasked 2×
- Q7An electric dipole of dipole moment 2 × 10^-8 C-m in a uniform electric field experiences a maximum torque of 6 × 10^-4…1 mk
- Q7A steady current of 8 mA flows through a wire. The number of electrons passing through a cross-section of the wire in…1 mk
- Q7For the forward biasing of a p-n junction diode, which of the following statements is not correct?1 mk
- Q8Two nuclei have their mass numbers in the ratio of 8: 1. The ratio of their nuclear densities is:1 mk
- Q8In the process of charging of a capacitor, the current produced between the plates of the capacitor is:1 mkasked 3×
- Q8Which of the following statements is not true for nuclear forces?1 mkasked 3×
- Q8Which one of the following has negative value of susceptibility?1 mk
- Q8Name the electromagnetic waves also known as 'heat waves'.1 mk
- Q8The SI unit of mobility of charge carriers is:1 mk
- Q8In the wave picture of light, the intensity I of light is related to the amplitude A of the wave as:1 mkasked 3×
- Q8The ratio of the nuclear densities of two nuclei having mass numbers 64 and 125 is1 mkasked 3×
- Q8A ray of monochromatic light propagating in air, is incident on the surface of water. Which of the following will be…1 mkasked 3×
- Q8Which one of the following elements will require the highest energy to take out an electron from them? Pb, Ge, C and Si1 mk
- Q9A point charge q 0 is moving along a circular path of radius a, with a point charge -Q at the centre of the circle. The…1 mk
- Q9During the formation of a p-n junction.1 mk
- Q9A conductor of 10 Ω is connected across a 6 V ideal source. The power supplied by the source to the conductor is1 mk
- Q9A beam of light travels from air into a medium. Its speed and wavelength in the medium are 1.5 × 10^8 ms^-1 and 230 nm…1 mk
- Q9The difference in mass of ^7 X nucleus and total mass of its constituent nucleons is 21.00 u. The binding energy per…1 mkasked 3×
- Q9The energy required by an electron to jump the forbidden band in silicon at room temperature is about1 mk
- Q9For a concave mirror of focal length ' f ', the minimum distance between the object and its real image is:1 mk
- Q9In a single-slit diffraction experiment, the width of the slit is halved. The width of the central maximum, in the…1 mkasked 3×
- Q9During the formation of a p-n junction:1 mk
- Q10The number of electrons flowing through a conductor per second is 3 · 3 × 10^19. The current flowing through the…1 mk
- Q10The threshold voltage for a p-n junction diode used in the circuit is 0 · 7 V. The type of biasing and current in the…1 mkasked 3×
- Q10Which one of the following metals does not exhibit emission of electrons from its surface when irradiated by visible…1 mk
- Q10The diagram shows four energy level of an electron in Bohr model of hydrogen atom. Identify the transition in which the…1 mkasked 2×
- Q10In a moving coil galvanometer, the deflecting torque τ acting on the coil is related to the current I flowing through…1 mk
- Q10The diagram shows four energy level of an electron in Bohr model of hydrogen atom. Identify the transition in which the…1 mk
- Q10A graph is plotted between the stopping potential (on y -axis) and the frequency of incident radiation (on x -axis) for…1 mk
- Q11The direction of induced current in the loop abc is:1 mkasked 3×
- Q11Hydrogen atom initially in the ground state, absorbs a photon which excites it to n=5 level. The wavelength of the…1 mkasked 3×
- Q11Which of the following graphs correctly represents the variation of a particle momentum with its associated de-Broglie…1 mk
- Q11Which of the following graphs correctly represents the variation of a particle momentum with its associated de-Broglie…1 mk
- Q11The current in a device varies with time t as I=6 t, where I is in mA and t is in s. The amount of charge that passes…1 mk
- Q11Figure shows a plot of stopping potential (V 0) versus 1/(λ), where λ is the wavelength of the radiation causing…1 mk
- Q11A hydrogen atom makes a transition from n=5 to n=1 orbit. The wavelength of photon emitted is λ. The wavelength of…1 mk
- Q11Light of frequency 6.4 × 10^14 Hz is incident on a metal of work function 2 · 14 eV. The maximum kinetic energy of the…1 mkasked 3×
- Q11A plane wavefront is incident on a concave mirror of radius of curvature R. The radius of the refracted wavefront will…1 mkasked 3×
- Q12A ray of light travels a distance of 12.0 m in a transparent sheet in 60 ns. The refractive index of the sheet is1 mk
- Q12A photon of wavelength 663 nm is incident on a metal surface. The work function of the metal is 1.50 eV. The maximum…1 mk
- Q12The ratio of maximum frequency and minimum frequency of light emitted in Balmer series of hydrogen spectrum, in Bohr's…1 mkasked 3×
- Q12An ac voltage v=v 0 sin ω t is applied to a series combination of a resistor R and an element X. The instantaneous…1 mkasked 3×
- Q12The mass density of a nucleus of mass number A is:1 mk
- Q12The capacitors, each of 4 μ F are to be connected in such a way that the effective capacitance of the combination is 6…1 mkasked 3×
- Q12Electromagnetic waves of wavelength of the order of a few meters were first produced and detected in the laboratory by:1 mk
- Q12A proton and an alpha particle have the same kinetic energy. The ratio of de Broglie wavelengths associated with the…1 mkasked 3×
- Q12The curve of binding energy per nucleon as a function of atomic mass number has a sharp peak for helium nucleus. This…1 mkasked 3×
- Q13The emf and internal resistance of a cell are E and r respectively. It is connected across an external resistance R=2…1 mk
- Q13Which of the following statements about a series LCR circuit connected to an ac source is correct?1 mk
- Q13An ideal inductor is connected across an AC source of voltage. The current in the circuit1 mk
- Q13In an extrinsic semiconductor, the number density of holes is 4 × 10^20 m^-3. If the number density of intrinsic…1 mkasked 3×
- Q13Which of the following pairs of media has the least value of critical angle?1 mk
- Q13An ac source of voltage is connected in series with a p-n junction diode and a load resistor. The correct option for…1 mkasked 3×
- Q13What is the ratio of inductive and capacitive reactance in an ac circuit?1 mk
- Q13The potential energy of an electron in the second excited state in hydrogen atom is:1 mkasked 3×
- Q14Pieces of copper and of silicon are initially at room temperature. Both are heated to temperature T. The conductivity of1 mk
- Q14According to Huygens principle, the amplitude of secondary wavelets is1 mkasked 2×
- Q14Which one of the following is the correct representation of variation of conductivity of a conductor with temperature?1 mk
- Q14If a p-n junction diode is reverse biased,1 mk
- Q14When an intrinsic semiconductor is doped with a small amount of trivalent impurity, then:1 mkasked 3×
- Q14Two cells of emf E each and internal resistances r and 2 r are connected in parallel as shown in the figure. The…1 mk
- Q14A ray of light of wavelength 600 nm propagates from air into a medium. If its wavelength in the medium becomes 400 nm,…1 mk
- Q14In an interference experiment, third bright fringe is obtained at a point on the screen with a light of 700 nm. What…1 mk
- Q14A bar magnet is dropped in a hollow metallic cylinder along its vertical axis. The acceleration of the falling magnet…1 mk
- Q15The radius of the n^ th orbit in Bohr model of hydrogen atom is proportional to1 mkasked 4×
- Q15The correct graph showing the variation of the resistance (R) of a cylindrical metal wire as a function of its radius (…1 mk
- Q15Which of the following graphs correctly represents the variation of the magnitude of the magnetic field outside a…1 mkasked 3×
- Q15A point charge situated at a distance ' r ' from a short electric dipole on its axis, experiences a force F. If the…1 mkasked 3×
- Q15A voltage signal is described by: for a cycle. Its rms value is:1 mk
- Q15In the energy-band diagram of n-type Si, the gap between the bottom of the conduction band E C and the donor energy…1 mk
- Q15The formation of depletion region in a p-n junction diode is due to1 mk
- Q16Assertion: The resistance of an intrinsic semiconductor decreases with increase in its temperature. Reason (R): The…1 mkasked 2×
- Q16Assertion: When a bar of copper is placed in an external magnetic field, the field lines get concentrated inside the…1 mkasked 3×
- Q16Assertion: When three electric bulbs of power 200 W, 100 W and 50 W are connected in series to a source, the power…1 mkasked 3×
- Q16Assertion: The internal resistance of a cell is constant. Reason (R): Ionic concentration of the electrolyte remains…1 mkasked 3×
- Q16Assertion: In insulators, the forbidden gap is very large. Reason (R): The valence electrons in an atom of an insulator…1 mk
- Q16Assertion: Diamagnetic substances exhibit magnetism. Reason (R): Diamagnetic materials do not have permanent magnetic…1 mkasked 3×
- Q17Assertion: The phase difference between any two points on a wavefront is zero. Reason (R): All points on a wavefront…1 mkasked 3×
- Q17Assertion: The given figure does not show a balanced Wheatstone bridge. Reason (R): For a balanced bridge small current…1 mk
- Q17Assertion: When radius of a circular loop carrying a steady current is doubled, its magnetic moment becomes four times.…1 mkasked 3×
- Q17Assertion: A current carrying square loop made of a wire of length L is placed in a magnetic field. It experiences a…1 mkasked 3×
- Q17Assertion: The equivalent resistance between points A and B in the given network is 2 R. Reason (R): All the resistors…1 mkasked 2×
- Q17Assertion: Work done in moving a charge around a closed path, in an electric field is always zero. Reason (R):…1 mkasked 3×
- Q18Assertion: In Young's double slit experiment all fringes are of equal width. Reason (R): The fringe width depends upon…1 mkasked 3×
- Q18Assertion: The nucleus 3^7 X is more stable than the nucleus 3^4 Y. Reason (R): 3^7 X contains more number of protons.1 mkasked 3×
- Q18Assertion: In 'n' type semiconductor, number density of electrons is greater than the number density of holes but the…1 mkasked 3×
- Q18Assertion: Photoelectric effect demonstrates the particle nature of light. Reason ( R ): Photoelectric current is…1 mkasked 3×
- Q18Assertion: The deflecting torque acting on a current carrying loop is zero when its plane is perpendicular to the…1 mkasked 3×
- Q19Draw a graph showing the variation of potential energy of a pair of nucleons as a function of their separation.…2 mk
- Q19Draw a graph showing the variation of potential energy of a pair of nucleons as a function of their separation.…2 mk
- Q19Briefly explain why and how a galvanometer is converted into an ammeter.2 mkasked 3×
- Q19An alpha particle is projected with velocity v=(3 · 0 × 10^5 m / s) i into a region in which magnetic field B=[(0 · 4…2 mkasked 3×
- Q19Two identical dipoles are arranged in x-y plane as shown in the figure. Find the magnitude and the direction of net…2 mk
- Q19How is the width of depletion layer of a p-n junction diode affected when it is (i) forward biased, and (ii) reverse…2 mk
- Q19Plot a graph showing the variation of photo electric current, as a function of anode potential for two light beams…2 mk
- Q19The radii of curvature of the faces of a double-convex lens are 20 cm and 30 cm. Its power is 25/6 D. What is the…2 mk
- Q19In a Young's double slit experiment, the separation between the two slits is d and distance of the screen from the…2 mk
- Q19A wire of length l is in the form of a circular loop A of one turn. This loop is reshaped into loop B of three turns.…2 mk
- Q20Consider an induced magnetic field due to changing electric field and an induced electric field due to changing…2 mk
- Q20Answer the following giving reasons: Do the magnetic field lines also represent the 'lines of force' on a moving…2 mk
- Q20How are infrared waves produced? Why are these waves referred to as heat waves? Give any two uses of infrared waves. OR…2 mkasked 3×
- Q20Briefly describe the multi-step process involved in the generation of energy in the Sun.2 mk
- Q20What is meant by the term 'displacement current'? Briefly explain how this current is different from a conduction…2 mkasked 3×
- Q20How will the De Broglie wavelength associated with an electron be affected when the (i) velocity of the electron…2 mkasked 3×
- Q20Write two differences between the emf and terminal potential difference of a cell. What is the most important…2 mk
- Q21Use Gauss's law to obtain the expression for electric field due to a thin infinitely long straight uniformly charged…2 mk
- Q21How are electromagnetic waves produced? Write their two characteristics.2 mk
- Q21A small magnetised needle P is placed at the origin of x-y plane with its magnetic moment pointing along the y -axis.…2 mk
- Q21Using Huygens' principle, draw a ray diagram showing the propagation of a plane wave refracting at a plane surface…2 mkasked 3×
- Q21State Huygens' principle. How did Huygens explain the absence of the backwave? OR Use Huygens' principle to show…2 mkasked 3×
- Q21Identify the electromagnetic radiation and write its wavelength range, which is used to kill germs in water purifier.…2 mk
- Q21With the help of a circuit diagram, explain how a full wave rectifier gives output rectified voltage corresponding to…2 mk
- Q21Identify the electromagnetic wave whose wavelengths range is from about 10^-12 m to about 10^-8 m. 10^-3 m to about…2 mk
- Q21In the given figure the radius of curvature of curved face in the plano- convex and the plano-concave lens is 15 cm…2 mk
- Q22Depict the orientation of an electric dipole in stable and unstable equilibrium in an external uniform electric field.…2 mk
- Q22The ground state energy of hydrogen atom is -13 · 6 eV in Bohr model. An electron makes a transition from an energy…2 mk
- Q22The refractive indices of two media A and B are 2 and √2 respectively. What is the critical angle for their interface?2 mkasked 3×
- Q22An electric dipole of dipole moment ( p) is kept in a uniform electric field E. Show graphically the variation of…2 mk
- Q22A wire of length L is bent round in the form of (i) a square, and then (ii) an equilateral triangle. If current I is…2 mk
- Q22Two coherent monochromatic light beams of intensities I and 4 I superpose each other. Find the ratio of maximum and…2 mk
- Q22What is a displacement current? How is it different from a conduction current? OR Write any two characteristics of an…2 mkasked 3×
- Q22A plane electromagnetic wave propagates in vacuum along x -axis. Give the direction of electric field and magnetic…2 mk
- Q22What happens to the interference pattern when two coherent sources are infinitely close, and far apart from each other2 mkasked 2×
- Q22A cell of emf E and internal resistance r is connected to a variable resistance R. Draw plots showing the variation of…2 mk
- Q22Three point charges Q, q and -q are kept at the vertices of an equilateral triangle of side L as shown in figure. What…2 mk
- Q23A particle of charge q and mass m starts moving with uniform velocity v 0 i. Specify the direction of magnetic field…2 mk
- Q23The figure shows v m^2 versus 1/(λ) graph for photoelectrons emitted from a surface where v m is the maximum speed of…2 mkasked 3×
- Q23Write the expression for the Lorentz force on a particle of charge q moving with a velocity v in a magnetic field B.…2 mk
- Q23Two identical circular loops P and Q, each of radius R carrying current I are kept in perpendicular planes such that…2 mk
- Q23What is meant by ionisation energy? Write its value for hydrogen atom. OR Define the term, mass defect. How is it…2 mkasked 3×
- Q23The power of a thin lens is +5 D. When it is immersed in a liquid, it behaves like a concave lens of focal length 100…2 mk
- Q23Show that the density of a nucleus is independent of its mass number. Why are lighter nuclei more stable than heavier…2 mk
- Q23The ground state energy of hydrogen atom is -13.6 eV. What is the potential energy and kinetic energy of an electron in…2 mk
- Q23Draw a graph showing the variation of binding energy per nucleon as a function of mass number A. The binding energy per…2 mkasked 3×
- Q23Two wires of equal lengths are shaped in the form of a square loop and a circular loop. Both loops are suspended in a…2 mk
- Q23Write the expression for the Lorentz force on a particle of charge q moving with a velocity v in a magnetic field B.…2 mk
- Q24Two conductors, made of the same material have equal lengths but different cross-sectional areas A 1 and A 2( A 1 A 2).…2 mk
- Q24Draw the graph showing the variation of binding energy per nucleon with mass number A of nuclei (2<A<170). Use this…2 mk
- Q24The potential difference applied across a given conductor is doubled. How will this affect (i) the mobility of…2 mk
- Q24A potential difference ( V ) is applied across a conductor of length ' L ' and cross-sectional area 'A'. How will the…2 mk
- Q24A double-convex lens of power 4 D is manufactured from a glass of refractive index 1 · 5. What is the radius of…2 mk
- Q24Differentiate between intrinsic and extrinsic semiconductors. OR Draw the circuit arrangement for studying the V-I…2 mkasked 3×
- Q24Identify the part of electromagnetic spectrum which is: next to the lowest frequency end of the visible part of…2 mk
- Q24Draw energy band diagram for an n -type and p -type semiconductor at T 0 K.2 mkasked 3×
- Q24Use Gauss's law to obtain the expression for electric field due to a uniformly charged infinite plane thin sheet.2 mk
- Q24Explain the roles of diffusion current and drift current in the formation of the depletion layer in a p-n junction…2 mk
- Q25Two coils C 1 and C 2 are placed close to each other. The magnetic flux φ 2 linked with the coil C 2 varies with the…2 mkasked 3×
- Q25A point object in air is placed symmetrically at a distance of 60 cm in front of a concave spherical surface of…2 mk
- Q25Calculate the wavelength of the second line of Lyman series in a spectrum of hydrogen atom. (Take Rydberg constant, R=1…2 mk
- Q25Answer the following giving reasons: (i) A p-n junction diode is damaged by a strong current. (ii) Impurities are added…2 mkasked 2×
- Q25Obtain an expression for electrostatic potential energy of a system of three charges q, 2 q and -3 q placed at the…2 mkasked 3×
- Q25Draw a circuit diagram of a p-n junction diode in forward biasing, and reverse biasing. Draw the V-I characteristics…2 mk
- Q25Briefly explain how the diffusion and drift currents contribute to the formation of potential barrier in a p-n junction…2 mkasked 3×
- Q25Two identical cells, each of emf E and internal resistance r, are connected with a load resistance R, first in series…2 mk
- Q25Explain the property of a p-n junction which makes it suitable for rectifying alternating voltages. Differentiate…2 mkasked 3×
- Q26A plane wave-front propagating in a medium of refractive index ' μ 1 ' is incident on a plane surface making an angle…3 mk
- Q26A particle of mass m and charge q is accelerated through a potential difference V. Plot a graph of de Broglie…3 mk
- Q26A potential difference V is applied across a conductor of length l and uniform cross-section area A. How will the (i)…3 mk
- Q26A series RL circuit with R=10 Ω and L=(100/(π)) mH is connected to an ac source of voltage V=141 sin (100 π t), where V…3 mk
- Q26A plane wave-front propagating in a medium of refractive index ' μ 1 ' is incident on a plane surface making an angle…3 mkasked 2×
- Q26Draw a plot showing the variation of potential energy of two nucleons as a function of distance between them. Identify…3 mk
- Q26Two circular loops A and B, each of radius 3 m, are placed coaxially at a distance of 4 m. They carry currents of 3 A…3 mk
- Q26Twelve negative charges of same magnitude are equally spaced and fixed on the circumference of a circle of radius R as…3 mk
- Q26An ac voltage v=v m sin ω t(v m=310 V. and.f=50 Hz) is connected to a pure capacitor of capacitance 15 μ F. Calculate…3 mk
- Q26A ray of light is refracted by a glass prism. Obtain an expression for the refractive index of the glass in terms of…3 mk
- Q26Two charged conducting spheres of radii a and b are connected to each other by a wire. Find the ratio of the electric…3 mkasked 3×
- Q27Define current density and relaxation time. Derive an expression for resistivity of a conductor in terms of number…3 mk
- Q27A ray of light is incident on a glass prism of refractive index μ and refracting angle A. If it just suffers total…3 mk
- Q27An alternating current I=14 sin (100 π t) A passes through a series combination of a resistor of 30 Ω and an inductor…3 mk
- Q27What is meant by the term 'mutual inductance' of a pair of coils? Obtain an expression for the mutual inductance of two…3 mk
- Q27How does the resistance differ from impedance? With the help of a suitable phasor diagram, obtain an expression for…3 mkasked 3×
- Q27A current of 1 A flows through a coil when it is connected across a DC battery of 100 V. If DC battery is replaced by…3 mk
- Q27(i) In diffraction due to a single slit, the phase difference between light waves reaching a point on the screen is 5…3 mkasked 3×
- Q27An alternating voltage of 220 V is applied across a device X. A current of 0.22 A flows in the circuit and it lags…3 mk
- Q27The threshold wavelength for a metal is 3315. What should be the wavelength of light incident on the metal surface so…3 mk
- Q27A current carrying circular loop and a straight wire bent partly in the form of a semicircle are placed as shown in the…3 mk
- Q27The figure shows the variation of induced emf as a function of rate of change of current for two identical solenoids X…3 mk
- Q28A long solenoid of radius r consists of n turns per unit length. A current I=I 0 sin ω t flows in the solenoid. A coil…3 mk
- Q28A resistor of 30 Ω and a capacitor of 250/(π) μ F are connected in series to a 200 V, 50 Hz ac source. Calculate (i)…3 mkasked 3×
- Q28The figure shows a rectangular conductor PQRS in which the arm PQ of length 10 cm and resistance 0 · 4 Ω is free to…3 mk
- Q28State the basic principle behind the working of an ac generator. Briefly describe its working and obtain the expression…3 mkasked 2×
- Q28The primary coil having N p turns of an ideal transformer is supplied with an alternating voltage V p. Obtain an…3 mk
- Q28Three point charges Q 1(-15 μ C), Q 2(10 μ C) and Q 3(16 μ C) are located at (0 cm, 0 cm),(0 cm, 3 cm) and (4 cm, 3 cm)…3 mk
- Q28A series CR circuit with R=200 Ω and C=(50 / π) μ F is connected across an ac source of peak voltage ε 0=100 V and…3 mk
- Q28An ac source v=v m sin ω t is connected across an ideal capacitor. Derive the expression for the (i) current flowing in…3 mkasked 3×
- Q28The primary and the secondary coils of an ideal step-down transformer consist of 650 and 25 turns respectively. When…3 mk
- Q28Differentiate between 'impact parameter' and 'distance of closest approach' in alpha particle scattering experiment.…3 mk
- Q29Calculate the wavelength of de Broglie waves associated with a proton having (500/(1 · 673)) eV energy. How will the…3 mk
- Q29A rectangular loop of sides 25 cm and 20 cm is lying in x-y plane. It is subjected to a magnetic field B=(5 t^2+2 t+10)…3 mk
- Q29How does Einstein's photoelectric equation explain the emission of electrons from a metal surface? Explain briefly.…3 mk
- Q29Define critical angle for a given pair of media and total internal reflection. Obtain the relation between the critical…3 mk
- Q29Briefly describe how the current sensitivity of a moving coil galvanometer can be increased. A galvanometer shows full…3 mkasked 3×
- Q29Two infinitely long parallel conductors A and B, separated by 2 cm, carry 6 A and 2 A currents in opposite directions…3 mk
- Q29Two cells of emf E 1 and E 2 and internal resistances r 1 and r 2 are connected in parallel, with their terminals of…3 mk
- Q29A potential difference V is applied across a conductor of length l and cross- sectional area A. Briefly explain how the…3 mk
- Q29Obtain a relation between the current flowing in a conductor and drift velocity of electrons in it. Hence, obtain Ohm's…3 mk
- Q30Two coplanar concentric circular loops of radii R and r( R) are arranged coaxially. Obtain the expression for their…3 mk
- Q30A particle is associated with a de Broglie wave of wavelength 1.2 nm. The kinetic energy of the particle is made four…3 mk
- Q30(i) Prove that the nuclear density is same for all nuclei. (ii) Draw a plot of potential energy of a pair of nucleons…3 mkasked 3×
- Q30Calculate the binding energy of an alpha particle in MeV. Given mass of a proton =1.007825 u mass of a neutron…3 mk
- Q30A resistor of 50 Ω, a capacitor of (25/(π)) μ F and an inductor of (4/(π)) H are connected in series across an ac…3 mk
- Q30A potential difference ' V ' is applied across a load resistor of resistance R. V and R can be varied. If the current…3 mk
- Q30Draw the energy level diagram for hydrogen atom. Mark the transitions corresponding to the series lying in the…3 mkasked 3×
- Q30A 100 μ F capacitor is charged by a 12 V battery. How much electrostatic energy is stored by the capacitor? The…3 mk
- Q30A rectangular conductor MNPQ with a movable arm MN (resistance r ) is kept in a uniform magnetic field as shown in the…3 mk
- Q30Briefly explain Geiger-Marsden experiment. Show the variation of the number of particles scattered ( N ) with…3 mk
- Q30The figure shows de Broglie wavelength ( λ ) for two particles A and B having same charges but different masses as a…3 mk
- Q30(i) Differentiate between 'distance of closest approach' and 'impact parameter'. (ii) Determine the distance of closest…3 mk
- Q30(i) Write the limitations of Rutherford's model of atom. (ii) The wavelength of the second line of the Balmer series in…3 mk
- Q30(i) Distinguish between nuclear fission and fusion giving an example of each. (ii) Explain the release of energy in…3 mkasked 3×
- Q31(i) Define electric flux and write its SI unit. (ii) Use Gauss' law to obtain the expression for the electric field due…5 mkasked 3×
- Q31(i) Use Gauss' law to obtain an expression for the electric field due to an infinitely long thin straight wire with…5 mkasked 3×
- Q31(i) State Coulomb's law in electrostatics and write it in vector form, for two charges. (ii) 'Gauss's law is based on…5 mkasked 3×
- Q31(i) Explain how free electrons in a metal at constant temperature attain an average velocity under the action of an…5 mkasked 2×
- Q32(i) (1) Write two points of difference between an interference pattern and a diffraction pattern. (2) Name any two…5 mkasked 3×
- Q32(i) Define coefficient of self-induction. Obtain an expression for self-inductance of a long solenoid of length l, area…5 mkasked 3×
- Q32Draw the circuit arrangement for studying V-I characteristics of a p-n junction diode in (i) forward biasing and (ii)…5 mkasked 3×
- Q32(i) Write the principle and explain the working of a moving coil galvanometer. A galvanometer as such cannot be used to…5 mkasked 3×
- Q32(i) State Biot-Savart's law for the magnetic field due to a current carrying element. Use this law to obtain an…5 mkasked 3×
- Q32(i) Draw a ray diagram to show how the final image is formed at infinity in an astronomical refracting telescope.…5 mkasked 3×
- Q33(i) Define mobility of electrons. Give its SI units. (ii) A steady current flows through a wire AB, as shown in the…5 mkasked 3×
- Q33(i) Draw a ray diagram to show the working of a compound microscope. Obtain the expression for the total magnification…5 mkasked 3×
- Q33(i) A germanium crystal is doped with antimony. With the help of energy-band diagram, explain how the conductivity of…5 mkasked 3×
- Q33(i) Draw a ray diagram showing the formation of a real image of an object placed at a distance ' u ' in front of a…5 mkasked 3×
- Q33(i) State Huygen's principle. With the help of a diagram, show how a plane wave is reflected from a surface. Hence…5 mkasked 3×
- Q34Figure shows the variation of photoelectric current measured in a photo cell circuit as a function of the potential…4 mkasked 3×
- Q34The following figure shows a circuit diagram. We can find the currents through and potential differences across…4 mkasked 3×
- Q34A capacitor is a system of two conductors separated by an insulator. The two conductors have equal and opposite charges…4 mkasked 3×
- Q34Consider the experimental set up shown in the figure. This jumping ring experiment is an outstanding demonstration of…4 mkasked 3×
- Q34Electrostatics deals with the study of forces, fields and potentials arising from static charges. Force and electric…4 mkasked 3×
- Q34A beam of electrons moving horizontally with a velocity of 3 × 10^7 m / s enters a region between two plates as shown…4 mkasked 2×
- Q34A lens is a transparent optical medium bounded by two surfaces; at least one of which should be spherical. Considering…4 mkasked 3×
- Q35Diffraction of light is bending of light around the corners of an object whose size is comparable with the wavelength…4 mkasked 3×
- Q35Strontium titanate is a rare oxide - a natural mineral found in Siberia. It is used as a substitute for diamond because…4 mkasked 3×
- Q35The lens maker's formula is useful to design lenses of desired focal lengths using surfaces of suitable radii of…4 mkasked 3×
Other Physics years
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