CBSE Class 12 Physics 2024
276 questions · 554 marks · 275 with the board’s own marking-scheme answer, 1 with no official answer on the site.
Marks by chapter
Counted from the 276 questions listed below, as the 2024 papers print them. CBSE allocates marks per unit, not per chapter — this is what was observed, not an official CBSE weightage. Every year compared →
| Chapter | Marks | Share |
|---|---|---|
| Current Electricity32 questions | 65 | 11.7% |
| Moving Charges and Magnetism37 questions | 63 | 11.4% |
| Electrostatic Potential and Capacitance22 questions | 63 | 11.4% |
| Ray Optics and Optical Instruments22 questions | 56 | 10.1% |
| Dual Nature of Radiation and Matter27 questions | 43 | 7.8% |
| Alternating Current18 questions | 39 | 7.0% |
| Atoms20 questions | 38 | 6.9% |
| Electromagnetic Induction21 questions | 36 | 6.5% |
| Semiconductor Electronics: Materials, Devices and Simple Circuits17 questions | 36 | 6.5% |
| Electromagnetic Waves19 questions | 34 | 6.1% |
| Wave Optics11 questions | 29 | 5.2% |
| Nuclei11 questions | 26 | 4.7% |
| Electric Charges and Fields13 questions | 18 | 3.2% |
| Magnetism and Matter6 questions | 8 | 1.4% |
276 questions from 2024
- Q1The plates P_1 and P_2 of a 2 μ F capacitor are at potentials 25 V and -25 V respectively. The charge on plate P_1 will…1 mk
- Q1Coulomb force F versus (1/(r^2)) graphs for two pairs of point charges ( q_1 and q_2 ) and ( q_2 and q_3 ) are shown in…1 mk
- Q1An isolated conductor, with a cavity, has a net charge +Q. A point charge +q is inside the cavity. The charges on the…1 mk
- Q1Two charges +q each are kept ' 2 a ' distance apart. A third charge -2 q is placed midway between them. The potential…1 mk
- Q1An ammeter and a voltmeter are connected in series to a battery. Their readings are noted as 'A' and 'V' respectively.…1 mk
- Q1A heater coil rated as ( P, V ) is cut into two equal parts. One of the parts is then connected to a battery of V volt.…1 mk
- Q1A battery supplies 0.9 A current through a 2 Ω resistor and 0.3 A current through a 7 Ω resistor when connected one by…1 mk
- Q1The capacitance of a parallel plate capacitor having a medium of dielectric constant K=4 in between the plates is C. If…1 mk
- Q1A thin plastic rod is bent into a circular ring of radius R. It is uniformly charged with charge density λ. The…1 mk
- Q1An electric dipole of dipole moment p is kept in a uniform electric field → E. The amount of work done to rotate it…1 mk
- Q1Three point charges, each of charge q are placed on vertices of a triangle ABC, with AB=AC=5 L, BC=6 L. The…1 mk
- Q1Consider a group of charges q_1, q_2, q_3 … such that Σ q ≠ 0. Then equipotentials at a large distance, due to this…1 mk
- Q1Two charged particles P and Q, having the same charge but different masses m_P and m_Q, start from rest and travel…1 mk
- Q2Three small charged spheres X, Y and Z carrying charges +q,-q and +q respectively are placed equidistant from each…1 mk
- Q2Electrons drift with speed v_d in a conductor with potential difference V across its ends. If V is reduced to (V/2),…1 mk
- Q2The Coulomb force (F) versus (1 / r^2) graphs for two pairs of point charges (q_1. and q_2 ) and ( q_2 and q_3 ) are…1 mk
- Q2A proton is taken from point P_1 to point P_2, both located in an electric field. The potentials at points P_1 and P_2…1 mk
- Q2Two identical small conducting balls B_1 and B_2 are given -7 pC and +4 pC charges respectively. They are brought in…1 mk
- Q2Ten capacitors, each of capacitance 1 μ F, are connected in parallel to a source of 100 V. The total energy stored in…1 mk
- Q2A particle of mass m and charge q describes a circular path of radius R in a magnetic field. If its mass and charge…1 mk
- Q2A charged sphere of radius r has surface charge density σ. The electric field on its surface is E. If the radius of the…1 mk
- Q2Two insulated concentric coils, each of radius R, placed at right angles to each other, carry currents I and √3 I…1 mk
- Q2An infinite long straight wire having a charge density λ is kept along y^′ y axis in x -y plane. The Coulomb force on a…1 mk
- Q2An ac voltage is applied across an ideal inductor. The current in it1 mk
- Q3A 2.0 cm segment of wire, carrying 5.0 A current in positive y-direction lies along y -axis, as shown in the figure.…1 mk
- Q3The emf induced in a coil rotating in a magnetic field does not depend upon the following:1 mk
- Q3Which of the following pairs is that of paramagnetic materials?1 mk
- Q3A conducting loop is placed in a magnetic field, normal to its plane. The magnitude of the magnetic field varies with…1 mk
- Q3An iron needle is kept near a strong bar magnet. It will experience1 mk
- Q3Which of the following material has its magnetic susceptibility x in the range 0<x<ε, where ε is positive and small?1 mk
- Q3A wire of length 4 · 4 m is bent round in the shape of a circular loop and carries a current of 1.0 A. The magnetic…1 mk
- Q3In a uniform straight wire, conduction electrons move along +x direction. Let E and j be the electric field and current…1 mk
- Q3A student is asked to connect four cells, each of emf E and internal resistance r, in series. But she/he connects one…1 mk
- Q3Consider the circuit shown in the figure. The potential difference between points A and B is:1 mk
- Q3The quantum nature of light explains the observations on photoelectric effect as -1 mk
- Q4A piece of wire bent in the form of a circular loop A carries a current I. The wire is then bent into a circular loop B…1 mk
- Q4Two charged particles, P and Q, each having charge q but of masses m_1 and m_2, are accelerated through the same…1 mk
- Q4The radius ( r_n ) of n^th orbit in Bohr model of hydrogen atom varies with n as1 mk
- Q4Two thin long parallel wires separated by a distance 'a' carry current ' I ' in opposite directions. The wires will:1 mk
- Q4A loop carrying a current I clockwise is placed in x-y plane, in a uniform magnetic field directed along z -axis. The…1 mk
- Q4Which of the following is a diamagnetic substance?1 mk
- Q4A circular coil of radius 10 cm is placed in a magnetic field B=(1.0 i+0.5 j) mT such that the outward unit vector…1 mk
- Q4A circular loop of wire, carrying a current ' I ' is lying in xy -plane with its centre coinciding with the origin. It…1 mk
- Q4A galvanometer of resistance 50 Ω is converted into a voltmeter of range (0-2 V) using a resistor of 1.0 k Ω. If it is…1 mk
- Q4A galvanometer of resistance 100 Ω gives full scale deflection for a current of 1.0 mA. It is converted into an ammeter…1 mk
- Q4A galvanometer shows full scale deflection for a current I_g. If a shunt of resistance S_1 is connected to the…1 mk
- Q5A current carrying circular loop of magnetic moment M is suspended in a vertical plane in an external magnetic field B…1 mk
- Q5A 10 cm long wire lies along y -axis. It carries a current of 1.0 A in positive y-direction. A magnetic field B=(5 mT)…1 mk
- Q5A straight wire is kept horizontally along east-west direction. If a steady current flows in wire from east to west,…1 mk
- Q5Which of the following quantity/quantities remains same in primary and secondary coils of an ideal transformer?…1 mk
- Q5The mutual inductance of two coils, in a given orientation is 50 mH. If the current in one of the coils changes as…1 mk
- Q5Two long straight parallel conductors A and B, kept at a distance r, carry current I in opposite directions. A third…1 mk
- Q5Two coils are placed near each other. When the current in one coil is changed at the rate of 5 A / s, an emf of 2 mV is…1 mk
- Q5A particle of mass m and charge q is moving with velocity v=v_x i+v_y j. If it is subjected to a magnetic field B=B_0…1 mk
- Q5A coil of area of cross-section 0.5 m^2 is placed in a magnetic field acting normally to its plane. The field varies as…1 mk
- Q6A resistor and an ideal inductor are connected in series to a 100 √2 V, 50 Hz ac source. When a voltmeter is connected…1 mk
- Q6The current in a coil of 15 mH increases uniformly from zero to 4 A in 0.004 s. The emf induced in the coil will be:1 mk
- Q6In an ac circuit, the instantaneous values of current (in A) and voltage (in V ) are I=5 sin ω t and E=200 cos (ω…1 mk
- Q6A series LCR circuit ( L=2 mH, C=0 · 2 μ F and R=30 Ω ) is connected to an ac source of variable frequency. The…1 mk
- Q6A coil of N turns is placed in a magnetic field B such that B is perpendicular to the plane of the coil. B changes with…1 mk
- Q6A galvanometer of resistance G Ω is converted into an ammeter of range 0 to IA. If the current through the galvanometer…1 mk
- Q6The mutual inductance of two coils C_1 and C_2 is 20 mH. In coil C_1, the current changes from 4 A to zero in 0 · 2 s.…1 mk
- Q6The electromagnetic waves used to purify water are1 mk
- Q6The average value of the alternating voltage v=(157 V) sin ω t over its first half-cycle is:1 mk
- Q6The magnetic susceptibility for a diamagnetic material is1 mk
- Q7Welders wear special glass goggles or face masks with glass windows to protect their eyes from radiations produced by…1 mk
- Q7Consider a solenoid of length l and area of cross-section A with fixed number of turns. The self-inductance of the…1 mk
- Q7A conducting circular loop is placed in a uniform magnetic field B=50 mT with its plane perpendicular to the magnetic…1 mk
- Q7Electromagnetic waves with wavelength 10 nm are called:1 mk
- Q7The reactance of a capacitor of capacitance C connected to an ac source of frequency ω is ' X '. If the capacitance of…1 mk
- Q7In four regions I, II, III and IV, the magnetic field is given by: I. B_y=B_0 sin kz II. B_y=B_0 cos kz III. B_y=B_0…1 mk
- Q7The primary and secondary coils of a transformer have 500 turns and 5000 turns respectively. The primary coil is…1 mk
- Q7A galvanometer of resistance 100 Ω is converted into an ammeter of range ( 0-1 A ) using a resistance of 0.1 Ω. The…1 mk
- Q7The focal lengths of the objective and the eyepiece of a compound microscope are 1 cm and 2 cm respectively. If the…1 mk
- Q8Which one of the following has the highest frequency?1 mk
- Q8A photosensitive surface has a work function of 2 · 00 eV. The maximum kinetic energy of electrons ejected from this…1 mk
- Q8Electromagnetic waves with frequency 1.0 × 10^18 Hz are known as:1 mk
- Q8The variation of the stopping potential ( V_0 ) with the frequency ( v ) of the incident radiation for four metals A,…1 mk
- Q8The work function for a photosensitive surface is 3 · 315 eV. The cut-off wavelength for photoemission of electrons…1 mk
- Q8The first scientist who produced and observed electromagnetic waves of wavelengths in the range 25 mm-5 mm was:1 mk
- Q8The momentum (in SI units) associated with a photon of energy 1 · 5 eV is:1 mk
- Q8The electric and magnetic fields of electromagnetic waves are:1 mk
- Q8A plane electromagnetic wave is travelling in air in +x direction. At a particular moment, its electric field E is…1 mk
- Q8In the four regions, I, II, III and IV, the electric fields are described as: Region I: E_x=E_0 sin (kz-ω t) Region II:…1 mk
- Q8In a Young's double-slit experiment in air, the fringe width is found to be 0.44 mm. If the entire setup is immersed in…1 mk
- Q8A circular loop A of radius R carries a current I. Another circular loop B of radius r(=R/20) is placed concentrically…1 mk
- Q9The transition of electron that gives rise to the formation of the second spectral line of the Balmer series in the…1 mk
- Q9Energy levels A, B and C of an atom correspond to increasing values of energy i.e. E_A<E_B<E_C. Let λ_1, λ_2 and λ_3 be…1 mk
- Q9Figure shows the variation of inductive reactance X_L of two ideal inductors of inductance L_1 and L_2, with angular…1 mk
- Q9The energy of an electron in the ground state of hydrogen atom is -13.6 eV. The kinetic and potential energy of the…1 mk
- Q9The r.m.s. value of a current given by i=(i_1 cos ω t+i_2 sin ω t) is -1 mk
- Q9An ac source V=282 sin (100 t) volt is connected across a 1 μ F capacitor. The rms value of current in the circuit will…1 mk
- Q9A proton and an alpha particle having equal velocities approach a target nucleus. They come momentarily to rest and…1 mk
- Q10The figure shows the variation of stopping potential V_0 with frequency v of incident radiation, for three materials…1 mk
- Q10The variation of the stopping potential ( V_0 ) with the frequency ( v ) of the incident radiation for four metals A,…1 mk
- Q10Ge is doped with As. Due to doping,1 mk
- Q10Which one of the following is the correct graph between the maximum kinetic energy ( K_m ) of the emitted…1 mk
- Q10A Young's double-slit experimental set up is kept in a medium of refractive index (4/3). Which maximum in this case…1 mk
- Q10The wavelength of matter wave associated with an electron of kinetic energy K is λ. If the kinetic energy of the…1 mk
- Q10An alpha particle approaches a gold nucleus in Geiger-Marsden experiment with kinetic energy K. It momentarily stops at…1 mk
- Q10The phase difference between electric field E and magnetic field B in an electromagnetic wave propagating along z -axis…1 mk
- Q11An electron makes a transition from n=2 level to n=1 level in the Bohr model of a hydrogen atom. Its period of…1 mk
- Q11The potential energy between two nucleons inside a nucleus is minimum at a distance of about1 mk
- Q11Two beams, A and B whose photon energies are 3 · 3 eV and 11 · 3 eV respectively, illuminate a metallic surface (work…1 mk
- Q11An n-type semiconducting Si is obtained by doping intrinsic Si with:1 mk
- Q12A pure Si crystal having 5 × 10^28 atoms m^-3 is dopped with 1 ppm concentration of antimony. If the concentration of…1 mk
- Q12When a p-n junction diode is subjected to reverse biasing:1 mk
- Q12In Balmer series of hydrogen atom, as the wavelength of spectral lines decreases, they appear1 mk
- Q12Si is doped with a pentavalent element. The energy required to set the additional electron free is about:1 mk
- Q12A point object is kept 60 cm in front of a spherical convex surface ( n=1.5, radius of curvature 40 cm ). The image…1 mk
- Q12The waves associated with a moving electron and a moving proton have the same wavelength λ. It implies that they have…1 mk
- Q13Assertion: Photoelectric current increases with an increase in intensity of incident radiation, for a given frequency…1 mk
- Q13Assertion: In a semiconductor, the electrons in the conduction band have lesser energy than those in the valence band.…1 mk
- Q13Assertion: In photoelectric effect, the kinetic energy of the emitted photoelectrons increases with increase in the…1 mk
- Q13Assertion: Electrons are ejected from the surface of zinc when it is irradiated by yellow light. Reason (R): Energy…1 mk
- Q13Assertion: Equal amount of positive and negative charges are distributed uniformly on two halves of a thin circular…1 mk
- Q14Assertion: The mutual inductance between two coils is maximum when the coils are wound on each other. Reason (R): The…1 mk
- Q14Assertion: Lenz's law is a consequence of the law of conservation of energy. Reason (R): There is no power loss in an…1 mk
- Q14Assertion: Photoelectric effect demonstrates the particle nature of light. Reason (R): Photoelectric current is…1 mk
- Q14Assertion: The energy of a charged particle moving in a magnetic field does not change. Reason (R): It is because the…1 mk
- Q14Assertion: The temperature coefficient of resistance is positive for metals and negative for p -type semiconductors.…1 mk
- Q15Assertion: A proton and an electron enter a uniform magnetic field B with the same momentum p such that p is…1 mk
- Q15Assertion: In a Young's double-slit experiment, interference pattern is not observed when two coherent sources are…1 mk
- Q15Assertion: Two long parallel wires, freely suspended and connected in series to a battery, move apart. Reason (R): Two…1 mk
- Q15Assertion: When electrons drift in a conductor, it does not mean that all free electrons in the conductor are moving in…1 mk
- Q15Assertion: An electron and a proton enter with the same momentum p in a magnetic field B such that p ⊥ B. Then both…1 mk
- Q16Assertion: A convex lens, when immersed in a liquid, disappears. Reason ( R ): The refractive indices of material of…1 mk
- Q16Assertion: In interference and diffraction of light, light energy reduces in one region producing a dark fringe. It…1 mk
- Q16Assertion: An alpha particle is moving towards a gold nucleus. The impact parameter is maximum for the scattering angle…1 mk
- Q16Assertion: The magnifying power of a compound microscope is negative. Reason (R): The final image formed is erect with…1 mk
- Q16Assertion: Plane and convex mirrors cannot produce real images under any circumstance. Reason ( R ): A virtual image…1 mk
- Q17What is meant by 'relaxation time' of free electrons in a conductor? Show that the resistance of a conductor can be…2 mk
- Q17Define resistivity of a conductor. How does the resistivity of a conductor depend upon the following: Number density of…2 mk
- Q17Four point charges of 1 μ C,-2 μ C, 1 μ C and -2 μ C are placed at the corners A, B, C and D respectively, of a square…2 mk
- Q17A uniform wire of length L and area of cross-section A has resistance R. The wire is uniformly stretched so that its…2 mk
- Q17An electric field E is maintained in a wire of length ' l ' and area of cross-section 'a'. Derive the relation between…2 mk
- Q17Find the temperature at which the resistance of a wire made of silver will be twice its resistance at 20^° C. Take 20^°…2 mk
- Q17Two batteries of emfs 6 V and 3 V and internal resistances 0 · 8 Ω and 0 · 2 Ω respectively are connected in series to…2 mk
- Q17"The electron drift speed is only a few mm / s for currents in the range of a few amperes for a given conductor." How…2 mk
- Q17Draw the circuit diagram of a p-n junction diode in (i) forward biasing and (ii) reverse biasing. Also draw its I-V…2 mk
- Q18The magnifying power of an astronomical telescope is 24. In normal adjustment, distance between its two lenses is 150…2 mk
- Q18Monochromatic light of frequency 5.0 × 10^14 Hz passes from air into a medium of refractive index 1 · 5. Find the…2 mk
- Q18Two waves, each of amplitude 'a' and frequency ' ω ' emanating from two coherent sources of light superpose at a point.…2 mk
- Q18Derive an expression for magnetic force F acting on a straight conductor of length L carrying current I in an external…2 mk
- Q18What are matter waves? A proton, an electron and an α -particle have the same kinetic energy. Write the de Broglie…2 mk
- Q18The ratio of de Broglie wavelengths of a proton and a deuteron accelerated by potential V_p and V_d respectively,…2 mk
- Q18A proton and α -particle are accelerated through different potentials V_1 and V_2 respectively so that they have the…2 mk
- Q19A convex lens (n = 1.52) has a focal length of 15.0 cm in air. Find its focal length when it is immersed in liquid of…2 mk
- Q19A telescope has an objective lens of focal length 150 cm and an eyepiece of focal length 5 cm. Calculate its magnifying…2 mk
- Q19A thin converging lens of focal length 10 cm is placed coaxially in contact with a thin diverging lens of focal length…2 mk
- Q19Explain the following: For a simple microscope, the angular size of the object equals the angular size of the image.…2 mk
- Q19What is a sustained or stable interference pattern? What are the conditions for obtaining such an interference pattern?2 mk
- Q19A ray of light is incident normally on one face of an equilateral glass prism of refractive index μ. When the prism is…2 mk
- Q19The radius of curvature of a convex mirror is 30 cm. It forms an image of an object which is half the size of the…2 mk
- Q19Write two points of difference between interference and diffraction of light.2 mk
- Q19An object is placed 30 cm in front of a concave mirror of radius of curvature 40 cm. Find the (i) position of the image…2 mk
- Q20Consider a neutron (mass m ) of kinetic energy E and a photon of the same energy. Let λ_n and λ_p be the de Broglie…2 mk
- Q20Deuterium undergoes the following fusion reaction: _1^2 H+_1^2 H →_2^3 He+_0^1 n+3.27 MeV How long an electric bulb of…2 mk
- Q20Two electric heaters have power ratings P_1 and P_2, at voltage V. They are connected in series to a dc source of…2 mk
- Q20Calculate the energy released/absorbed in the following nuclear reaction: _6^12 C+_6^12 C →_10^20 Ne+_2^4 He Given:…2 mkasked 2×
- Q20Two wires A and B of different metals have their lengths in ratio 1: 2 and their radii in ratio 2:1 respectively. I-V…2 mk
- Q20In Bohr model of hydrogen atom, find the ratio of period of revolution of the electron in the orbit n = 2 to that in…2 mk
- Q20Two energy levels of an electron in hydrogen atom are separated by 2.55 eV. Find the wavelength of radiation emitted…2 mk
- Q20The carbon isotope _6^12C has a nuclear mass of 12.000000 u. Calculate the binding energy of its nucleus. Given m_p =…2 mk
- Q20Find the temperature at which the resistance of a conductor increases by 25% of its value at 27 °C. The temperature…2 mk
- Q20Light of wavelength 500 nm is incident on caesium metal (work function 2 · 14 eV ) and photoemission of electrons…2 mk
- Q20Calculate the energy released/absorbed (in MeV ) in the nuclear reaction: _1^1 H+_1^3 H →_1^2 H+_1^2 H; Given: m(_1^1…2 mk
- Q20Light of wavelength 600 nm is incident on potassium (work function 2.3 eV). Will photoemission of electrons occur? What…2 mk
- Q20The minimum intensity of white light that our eyes can perceive is about 0.1 nWm^-2. Calculate the number of photons of…2 mk
- Q21How does the energy gap of an intrinsic semiconductor effectively change when doped with a trivalent impurity, and…2 mk
- Q21An air bubble is trapped at point B(CB=20 cm) in a glass sphere of radius 40 cm and refractive index 1.5 as shown in…2 mk
- Q21Suppose a pure Si crystal has 5 × 10^28 atoms m^-3. It is doped by 1 ppm concentration of boron. Calculate the…2 mk
- Q21How does the conductivity of an intrinsic semiconductor vary with temperature? Explain. Show the variation in a plot.2 mk
- Q21Differentiate between 'diffusion current' and 'drift current'. Explain their role in the formation of p-n junction.2 mk
- Q21Plot a graph showing the variation of current with voltage for the material GaAs. On the graph, mark the region where:…2 mk
- Q21The electron in hydrogen atom is revolving with the speed of 2.2 × 10^6 m / s in an orbit of radius 0.53. Calculate the…2 mk
- Q21The earth revolves around the sun in an orbit of radius 1.5 × 10^11 m with orbital speed 30 km / s. Find the quantum…2 mk
- Q21A proton of energy 1.6 MeV approaches a gold nucleus ( Z=79 ). Find the distance of its closest approach.2 mk
- Q22Determine the current in branches AB, AC and BC of the network shown in figure.3 mk
- Q22The figure shows a circuit with three ideal batteries. Find the magnitude and direction of currents in the branches AG,…2 mk
- Q22An air-filled parallel plate capacitor with plate separation 1 mm has a capacitance of 20 pF. It is charged to 4.0 μ C.…3 mk
- Q22A battery of unknown emf E and internal resistance r is connected in a circuit as shown in the figure. When the key ( K…3 mk
- Q22Three point charges Q_1, Q_2 and Q_3 are located in x-y plane at points (-d, 0),(0,0) and (d, 0) respectively. Q_1 and…3 mk
- Q22Write Einstein's photoelectric equation. How did Millikan prove the validity of this equation? Explain the existence of…3 mk
- Q22A current of 1.6 A flows through a wire when a potential difference of 1.0 V is applied across it. The length and…3 mk
- Q22A cube of side 0 · 1 m is placed, as shown in the figure, in a region where electric field E=500 × i exists. Here x is…3 mk
- Q22A photosensitive surface of work function 2.1 eV is irradiated by radiation of wavelength 150 nm. Calculate (i) the…3 mk
- Q22Differentiate between nuclear fission and fusion. The fission properties of _94 Pu^239 are very similar to those of _92…3 mk
- Q23A thin spherical conducting shell of radius R has a charge q. A point charge Q is placed at the centre of the shell.…3 mk
- Q23The threshold frequency for a metal is 3.0 × 10^14 Hz. A beam of frequency 9.0 × 10^14 Hz is incident on the metal.…3 mk
- Q23Define the term 'electric flux' and write its dimensions. A plane surface, in shape of a square of side 1 cm is placed…3 mk
- Q23The electric field in a region is given by E=(10 x+4) i where x is in m and E is in N/C. Calculate the amount of work…3 mk
- Q23An electron (charge - e, mass m ) is revolving around a nucleus, in a hydrogen atom, in a circle of radius r. Derive an…3 mk
- Q23On what factors does the speed of an electromagnetic wave in a medium depend? How is an electromagnetic wave produced?…2 mk
- Q23Two long straight parallel conductors carrying currents, exert a force on each other. Why? Derive an expression for the…3 mk
- Q23Two conducting spherical shells A and B of radii R and 2 R are kept far apart and charged to the same charge density σ.…3 mk
- Q23A rectangular loop of area A, carrying current I, is placed in a uniform magnetic field B. With the help of a suitable…3 mk
- Q23Define 'current density'. Is it a scalar or a vector? An electric field E is maintained in a metallic conductor. If n…3 mk
- Q24Distinguish between reactance and impedance of an ac circuit. Show that an ideal inductor in an ac circuit does not…3 mk
- Q24A 100 -turn coil of radius 1.6 cm and resistance 5.0 Ω is co-axial with a solenoid of 250 turns / cm and radius 1.8 cm.…2 mk
- Q24Draw the graph showing variation of scattered particles detected ( N ) with the scattering angle ( θ ) in…3 mk
- Q24A sinusoidal voltage is applied to an electric circuit containing a circuit element ' X ' in which the current leads…3 mk
- Q24Prove that induced charge depends on the net change in the magnetic flux and not on the time interval of the flux…3 mk
- Q24An ac voltage v_i=140 sin (100 π t) V is applied to the primary coil having 200 turns, of an ideal transformer and it…2 mk
- Q24A rectangular loop of sides 10 cm × 20 cm is kept outside a region of uniform magnetic field | B|=5 mT as shown in the…3 mk
- Q24A circular coil with cross-sectional area 0.2 cm^2 carries a current of 4 A. It is kept in a uniform magnetic field of…3 mk
- Q24(i) State Lenz's Law. In a closed circuit, the induced current opposes the change in magnetic flux that produced it as…3 mk
- Q24A proton with kinetic energy 1.3384 × 10^-14 J moving horizontally from north to south, enters a uniform magnetic field…3 mk
- Q24(i) Define 'temperature coefficient of resistance' of a metal. (ii) Show the variation of resistivity of copper with…3 mk
- Q24A bar magnet of magnetic moment 2 · 5 JT^-1 lies aligned with the direction of a uniform magnetic field of 0 · 32 T.…3 mk
- Q25In the given network, calculate: (i) effective resistance between points A and M, and (ii) power supplied by the…3 mk
- Q25Two long, straight, parallel conductors carry steady currents in opposite directions. Explain the nature of the force…2 mk
- Q25Consider the arrangement of two coils P and Q shown in the figure. When current in coil P is switched on or switched…3 mk
- Q25The electric field in an electromagnetic wave in vacuum is given by: E=(6 · 3 N / C)[ cos (1 · 5 rad / m) y+(4 · 5 ×…3 mk
- Q25Draw the graphs showing the variation of the following with the frequency of ac source in a circuit: (i) Resistance…3 mk
- Q25Two long insulated straight wires carrying currents of 3 A and 5 A are arranged in XY plane as shown in figure. Find…3 mk
- Q25Name the part of the electromagnetic spectrum which are (i) stopped by face mask worn by welders. (ii) used in…3 mk
- Q25An electron moving with a velocity v=(1.0 × 10^7 m / s) i+(0.5 × 10^7 m / s) j enters a region of uniform magnetic…3 mk
- Q25An inductor, a capacitor and a resistor are connected in series with an ac source v=v_m sin ω t. Derive an expression…3 mk
- Q25Find the current in branch BM in the network shown:3 mk
- Q26State Bohr's first and second postulates. Use them to derive an expression for the radius of the n^th orbit in a…3 mk
- Q26Name the parts of the electromagnetic spectrum which are (i) also known as 'heat waves' and (ii) absorbed by ozone…3 mk
- Q26Explain the origin of the spectral lines of hydrogen atom using Bohr's theory. Draw the energy level diagram of…3 mk
- Q26Briefly discuss three characteristics of the forces between nucleons. Which out of _4^8 X and _3^5 Y nuclei is more…2 mk
- Q26What is meant by displacement current? How is this current different from the conduction current? A capacitor is being…3 mk
- Q26A circular loop of radius 10 cm carrying current of 1.0 A lies in x-y plane. A long straight wire lies in the same…3 mk
- Q26Briefly explain de Broglie hypothesis for wave nature of matter. Find the ratio of de Broglie wavelength associated…3 mk
- Q26Using Bohr's postulates, derive the expression for the radius of the n^th orbit of an electron in a hydrogen atom. Also…2 mk
- Q26State Bohr's second postulate for his theory of hydrogen atom. Prove that the radius of Bohr's orbit of a hydrogen atom…3 mk
- Q26An infinite straight conductor is kept along X^′ X axis and carries a current I. A charge q at point P(0, r) starts…3 mk
- Q26"The wavelength of the electromagnetic wave is often correlated with the characteristic size of the system that…3 mk
- Q27de Broglie wavelength λ as a function of 1/(√ K), for two particles of masses m_1 and m_2 are shown in the figure.…2 mk
- Q27Plot a graph depicting potential energy of a pair of nucleons in a nucleus as a function of their separation. Identify…3 mk
- Q27State the three postulates of Bohr's theory of hydrogen atom. A hydrogen atom de-excites from level n to level ( n-1 ).…3 mk
- Q27Name the electromagnetic waves with their wavelength range which are used for (i) FM radio broadcast (ii) detection of…3 mk
- Q27Find the currents flowing through the branches AB and BC in the network shown.3 mk
- Q27Write the drawbacks of Rutherford's atomic model. How did Bohr remove them? Show that different orbits in Bohr's atom…3 mk
- Q27Explain the characteristics of a p-n junction diode that makes it suitable for its use as a rectifier. With the help of…3 mk
- Q27An electron is moving with a velocity v=(3 × 10^6 m/s) i. It enters a region of magnetic field B=(91 mT) k. Calculate…3 mk
- Q27Explain the following giving reasons: (i) 'Electromagnetic waves differ considerably in their mode of interaction with…3 mk
- Q27Define atomic mass unit (u). Calculate the energy required to separate a deuteron into its constituent parts (a proton…3 mk
- Q27Draw a schematic arrangement of Geiger-Marsden experiment. Briefly explain the conclusions drawn from the observations…2 mk
- Q28Draw the circuit diagrams for obtaining the V-I characteristics of a p-n junction diode. Explain briefly the salient…3 mk
- Q28A potential difference of 1.0 V is applied across a conductor of length 5.0 m and area of cross-section 1.0 mm^2. When…3 mk
- Q28Explain the following, giving reasons: A doped semiconductor is electrically neutral. In a p-n junction under…3 mk
- Q28(i) Define mutual inductance. Write its SI unit. (ii) Derive an expression for the mutual inductance of a system of two…3 mk
- Q28Write two characteristic properties of nuclear force. Draw a plot of potential energy of a pair of nucleons as a…3 mk
- Q28Draw the circuit diagrams for obtaining the V-I characteristics of a p-n junction diode. Explain briefly the salient…3 mk
- Q28State any two properties of a nucleus. Why is the density of a nucleus much more than that of an atom? Show that the…3 mk
- Q29The figure shows four pairs of parallel identical conducting plates, separated by the same distance 2.0 cm and arranged…4 mk
- Q29When the terminals of a cell are connected to a conductor of resistance R, an electric current flows through the…4 mk
- Q29A lens is a transparent medium bounded by two surfaces, with one or both surfaces being spherical. The focal length of…4 mk
- Q30Dielectrics play an important role in design of capacitors. The molecules of a dielectric may be polar or non-polar.…4 mk
- Q30A lens is a transparent optical medium bounded by two surfaces; at least one of which should be spherical. Applying the…4 mk
- Q30A prism is an optical medium bounded by three refracting plane surfaces. A ray of light suffers successive refractions…4 mk
- Q30Junction Diode as a Rectifier: The process of conversion of an ac voltage into a dc voltage is called rectification and…4 mk
- Q30A pure semiconductor like Ge or Si, when doped with a small amount of suitable impurity, becomes an extrinsic…4 mk
- Q30Diffraction and interference are closely related phenomena that occur together. Diffraction is the phenomenon of…4 mk
- Q30When a ray of light propagates from a denser medium to a rarer medium, it bends away from the normal. When the incident…4 mk
- Q31(i) Derive an expression for potential energy of an electric dipole p in an external uniform electric field E. When is…5 mk
- Q31(i) Obtain an expression for the electric potential due to a small dipole of dipole moment p, at a point r from its…5 mk
- Q31(i) Draw equipotential surfaces for an electric dipole. (ii) Two point charges q_1 and q_2 are located at r_1 and r_2…5 mk
- Q31(i) Obtain the expression for the capacitance of a parallel plate capacitor with a dielectric medium between its…5 mk
- Q31(i) Draw a ray diagram for the formation of the image of an object by a convex mirror. Hence, obtain the mirror…5 mk
- Q31(i) Give any two differences between the interference pattern obtained in Young's double-slit experiment and a…5 mk
- Q31(i) Obtain the expression for the capacitance of a parallel plate capacitor with a dielectric medium between its…5 mk
- Q32(i) A dielectric slab of dielectric constant ' K ' and thickness ' t ' is inserted between plates of a parallel plate…5 mk
- Q32(i) A resistor and a capacitor are connected in series to an ac source v=v_m sin ω t. Derive an expression for the…5 mk
- Q32(i) (1) What is meant by current sensitivity of a galvanometer? Mention the factors on which it depends. (2) A…5 mk
- Q33(i) A particle of mass m and charge q is moving with a velocity v in a magnetic field B as shown in the figure. Show…5 mk
- Q33(i) Give any two differences between the interference pattern obtained in Young's double-slit experiment and a…5 mk
- Q33(i) Trace the path of a ray of light showing refraction through a triangular prism and hence obtain an expression for…5 mk
- Q33(i) A plane light wave propagating from a rarer into a denser medium, is incident at an angle i on the surface…5 mk
- Q33(i) A ray of light passes through a triangular prism. Show graphically, how the angle of deviation varies with the…5 mk
- Q33(i) You are given three circuit elements X, Y and Z. They are connected one by one across a given ac source. It is…5 mk
- Q33(i) Mention the factors on which the resonant frequency of a series LCR circuit depends. Plot a graph showing variation…5 mk
Other Physics years
Answers come from CBSE’s own marking schemes. How we source them.