CBSE Class 12 Physics Answer Key 2024 (Available): Detailed solutions PDF download

Updated On: April 02, 2024 01:04 pm IST

Students can access CBSE Class 12 Physics answer key 2024 here and evaluate their tentative marks in the March 4 exam. The answer key is provided for all question paper sets.

CBSE Class 12 Physics Answer Key 2024 (Image Credit: Pexels)

CBSE Class 12 Physics Answer Key 2024: Students who attempted CBSE Class 12 Physics (theory) examination held on March 4, 2024 can check answers to objective questions on this page. Our experts will draft answer keys for Section A and Section D only. A total of 16 multiple-choice questions of 1 mark each are asked in Section A, out of which four are based on assertion reason. Section D comprises 2 case-based questions of 4 marks which are objective type. Therefore, answers to all such questions can be checked here and performance for the AY 2023-2024 in the Physics paper can be analysed. The answer keys for other sections are not available as their evaluation varies depending on the student's writing style and presenting the answers.

Helpful links for the next exam \|
CBSE Class 12 Mathematics Weightage 2024
CBSE Class 12 Mathematics Blueprint 2024

Note: CBSE 12th Physics Answer Key 2024 are available for QP Code: 55/4/3 (Set 3), QP Code: 55/4/2 (Set 2), QP Code: 55/1/2 (Set 2), QP Code: 55/2/3 (Set 3), and QP Code: 55/4/1 (Set 1).

Also Read | CBSE Class 12 Result Expected Release Date 2024

CBSE Class 12 Physics Answer Key 2024 for QP Code: 55/4/3

Section A comprises 16 multiple-choice questions out of which 4 are based on Assertion Reasoning of 1 mark each, the answers to which for QP Code: 55/4/3 are provided here in tabular format.

Question	QP Code: 55/4/3
1. An electric dipole of dipole moment p is kept in a uniform electric field E. The amount of work done to rotate it from the position of stable equilibrium to that of unstable equilibrium will be	(A) 2pE
2. An infinite long straight wire having a charge density a is kept along y'y axis in x-y plane. The Coulomb force on a point charge q at a point P (x, 0) will be	(A) attractive and qλ/2πε₀x
3. The phase difference between electric field E and magnetic field B in an electromagnetic wave propagating along z-axis is -	(A) Zero
4. In Balmer series of hydrogen atom, as the wavelength of spectral lines decreases, they appear	(D) closer together and weaker in intensity.
5. Two long straight parallel conductors A and B, kept at a distance r, carry current I in opposite directions. A third identical conductor C, kept at a distance (r/3): from A carry current I₁ in the same direction as in A. The net magnetic force on unit length of C is	(A) 3μ₀I I1/2πr, towards A
6. A coil of N turns is placed in a magnetic field such that B is perpendicular to the plane of the coal vec R changes with time as B=B₀ cos (2πt/T) where T is time period. The magnitude of emf induced in the coil will be maximum at	(C) t = nT/2
7. A circular loop A of radius R carries a current L. Another circular loop B of radius r (= R/20) placed concentrically in the plane of A. The magnetic flux linked with loop B is proportional to	(C) R^2/3
8. A galvanometer of resistance 100 Q is converted into an ammeter of range (0 - 1 A) using a resistance of 0.1 Q. The ammeter will show full scale deflection for a current of about	(C) 10 mA
9. The r.m.s. value of a current given by i = (i1 cos ωt + i2 sin ωt) is -	(C) [ ( i₁² + i₂² ) ] / 2^1/2
10. The quantum nature of light explains the observations on photoelectric effect as -	(A) there is a minimum frequency of incident radiation below which no electrons are emitted.
11. The magnetic susceptibility for a diamagnetic material is	(A) small and negative
12. The radius (r_n) of nth orbit in Bohr model of hydrogen atom varies with n	(C) r_n ∝ n²
13. Assertion (A): When electrons drift in a conductor, it does not mean that all free electrons in the conductor are moving in the same direction. Reason (R): The drift velocity is superposed over large random velocities of electrons.	(A) If both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
14. Assertion (A) : In interference and diffraction of light, light energy reduces in one region producing a dark fringe. It increases in another region and produces a bright fringe. Reason (R): This happens because energy is not conserved in the phenomena of interference and diffraction.	(A) If both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
15. Assertion (A) : The temperature coefficient of resistance is positive for metals and negative for p-type semiconductors. Reason (R): The charge carriers in metals are negatively charged. whereas the majority charge carriers in p-type semiconductors are positively charged.	(B) If both Assertion (A) and Reason (R) are true and Reason (R) is not the correct explanation of Assertion (A).
16. Assertion (A): Electrons are ejected from the surface of zinc when it is irradiated by yellow light. Reason (R): Energy associated with a photon of yellow light is more than the work function of zinc.	(C) If Assertion (A) is true and Reason (R) is false.

CBSE Class 12 Physics Answer Key 2024 for QP Code: 55/4/2

Section A comprises 16 multiple-choice questions out of which 4 are based on Assertion Reasoning of 1 mark each, the answers to which for QP Code: 55/4/2 are provided here in tabular format.

Question	QP Code: 55/4/2
1. Three point charges, each of charge q are placed on vertices of a triangle ABC, with AB = AC = 5L, BC = 6L. The electrostatic potential at midpoint of side BC will be	(A) 11q/48πε₀L
2. Coulomb force F versus (1/r²) graphs for two pairs of point charges (q₁ and q₂) and (q₂ and q₃) are shown in the figure. The charge q₂ is positive and gas least magnitude. Then	(C) q₃ > q₂ > q₁
3. The magnetic susceptibility for a diamagnetic material is	(A) small and negative
4. A circular loop A of radius R carries a current L. Another circular loop B of radius r (= R/20) placed concentrically in the plane of A. The magnetic flux linked with loop B is proportional to	(C) R^2/3
5. A particle of mass m and charge q is moving with velocity v = v_xi + v_yj If it is subjected to a magnetic field B = B₀i, it will move in a	(B) circular path
6. The quantum nature of light explains the observations on photoelectric effect as -	(A) there is a minimum frequency of incident radiation below which no electrons are emitted.
7. The phase difference between electric field E and magnetic field B in an electromagnetic wave propagating along z-axis is -	(A) Zero
8. The radius (r_n) of nth orbit in Bohr model of hydrogen atom varies with n	(C) r_n ∝ n²
9. An ac source V = 282 sin (100 t) volt is connected across a 1 µF capacitor. The rms value of current in the circuit will be (take √2 = 1.41)	(B) 20 mA
10. A galvanometer of resistance 100 Q is converted into an ammeter of range (0 - 1 A) using a resistance of 0.1 Q. The ammeter will show full scale deflection for a current of about	(C) 10 mA
11. In Balmer series of hydrogen atom, as the wavelength of spectral lines decreases, they appear	(D) closer together and weaker in intensity.
12. A coil of N turns is placed in a magnetic field such that B is perpendicular to the plane of the coal vec R changes with time as B=B₀ cos (2πt/T) where T is time period. The magnitude of emf induced in the coil will be maximum at	(C) t = nT/2
13. Assertion (A) : In interference and diffraction of light, light energy reduces in one region producing a dark fringe. It increases in another region and produces a bright fringe. Reason (R): This happens because energy is not conserved in the phenomena of interference and diffraction.	(A) If both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
14. Assertion (A): When electrons drift in a conductor, it does not mean that all free electrons in the conductor are moving in the same direction. Reason (R): The drift velocity is superposed over large random velocities of electrons.	(A) If both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
15. Assertion (A): Electrons are ejected from the surface of zinc when it is irradiated by yellow light. Reason (R): Energy associated with a photon of yellow light is more than the work function of zinc.	(C) If Assertion (A) is true and Reason (R) is false.
16. Assertion (A) : The temperature coefficient of resistance is positive for metals and negative for p-type semiconductors. Reason (R): The charge carriers in metals are negatively charged. whereas the majority charge carriers in p-type semiconductors are positively charged.	(B) If both Assertion (A) and Reason (R) are true and Reason (R) is not the correct explanation of Assertion (A).

CBSE Class 12 Physics Answer Key 2024 for QP Code: 55/1/2

Section A comprises 16 multiple-choice questions out of which 4 are based on Assertion Reasoning of 1 mark each, the answers to which for QP Code: 55/1/2 are provided here in tabular format.

Question	QP Code: 55/1/2
1. A thin plastic rod is bent into a circular ring of radius R. It is uniformly charged with charge density . The magnitude of the electric field at its centre is:	(C) λ/4πε₀R
2. A charged sphere of radius r has surface charge density o. The electric field on its surface is E. If the radius of the sphere is doubled, keeping charge density the same, the ratio of the electric field on the old sphere to that on the new sphere will be :	(C) 1/4
3. A student is asked to connect four cells, each of emf E and internal resistance r, in series. But she/he connects one cell wrongly in series with the other cells. The equivalent emf and the equivalent internal resistance of the combination will be :	(D) 2E and 4r
4. A 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 of two turns and carries the same current. The ratio of magnetic fields at the centre of loop A to that of loop B will be :	(C) 4
5. A 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)j - (8mT)k exists in the region. The force on the wire is:	(A) (0.8 mN)i
6. A galvanometer of resistance Go is converted into an ammeter of range O to I A. If the current through the galvanometer is 0.1% of I A, the resistance of the ammeter is:	(A) G/999 ohms
7. A conducting circular loop is placed in a uniform magnetic field B = 50 mT with its plane perpendicular to the magnetic field. The radius of the loop is made to shrink at a constant rate of 1 mm s^-1 At the instant the radius of the loop is 4 cm, the induced emf in the loop is:	(C) 4πμV
8. The electric and magnetic fields of electromagnetic waves are:	(A) In the same phase and perpendicular to each other.
9. Two beams, A and B whose photon energies are 3.3 eV and 11.3 eV respectively, illuminate a metallic surface (work function 2-3 eV) successively. The ratio of maximum speed of electrons emitted due to beam A to that due to beam B is:	(C) 1/3
10. The waves associated with a moving electron and a moving proton have the same wavelength. It implies that they have the same :	(A) momentum
11. Ge is doped with As. Due to doping,	(B) the number of conduction electrons increases.
12. The transition of electron that gives rise to the formation of the second spectral line of the Balmer series in the spectrum of hydrogen atom corresponds to :	(D) n_f = 2 and n_i = ∞
13. Assertion (A): Plane and convex mirrors cannot produce real images under any circumstance. Reason (R): A virtual image cannot serve as an object to produce a real image.	(C) Assertion (A) is true, but Reason (R) is false.
14. Assertion (A): Two long parallel wires, freely suspended and connected in series to a battery, move apart. Reason (R): Two wires carrying current in opposite directions repel each other.	(A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
15. Assertion (A): In photoelectric effect, the kinetic energy of the emitted photoelectrons increases with increase in the intensity of the incident light. Reason (R): Photoelectric current depends on the wavelength of the incident light.	(A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
16. Assertion (A): The mutual inductance between two coils is maximum when the coils are wound on each other. Reason (R): The flux linkage between two coils is maximum when they are wound on each other.	(A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).

CBSE Class 12 Physics Answer Key 2024 for QP Code: 55/2/3

Section A comprises 16 multiple-choice questions out of which 4 are based on Assertion Reasoning of 1 mark each, the answers to which for QP Code: 55/2/3 are provided here in tabular format.

Question	QP Code: 55/2/3
1. Coulomb force F versus (1/r²) graphs for two pairs of point charges (q₁ and q₂) and (q₂ and q₃) are shown in the figure. The ratio of charges (q₁/q₃) is:	(D) 1/3
2. Electrons drift with speed v_d in a conductor with potential difference V across its ends. If V is reduced to V/2 their drift speed will become :	(A) v_d/2
3. The emf induced in a coil rotating in a magnetic field does not depend upon the following:	(B) Resistance of the coil
4. A circular coil of radius 10 cm is placed in a magnetic field B = (1.0i+0.5j) mT such that the outward unit vector normal to the = surface of the coil is (0.6i + 0.8j). The magnetic flux linked with the coil is:	To be updated
5. Which of the following quantity/quantities remains same in primary and secondary coils of an ideal transformer? Current, Voltage, Power, Magnetic flux	(C) Power only
6. In an ac circuit, the instantaneous values of current (in A) and voltage = 5 sin ωt and E = 200 cos (ωt + π/3) respectively. The phase (in V) are I = difference between voltage and current at any instant is:	(A) 5π/6
7. In four regions I, II, III and IV, the magnetic field is given by: The electromagnetic wave will exist in the region :	(C) III: B_y = B₀ sin(kz - ωt)
8. The momentum (in SI units) associated with a photon of energy 1.5 eV is:	(D) 6 x 10^-29
9. An n-type semiconducting Si is obtained by doping intrinsic Si with :	(C) P
10. Energy levels A, B and C of an atom correspond to increasing values of energy i.e. E_A<E_B<E_C Let λ₁, λ₂ and λ₃ be the wavelengths of radiation corresponding to the transitions C to B, B to A and C to A, respectively. The correct relation between λ₁, λ₂ and λ₃	1/λ₁+ 1/λ₂ = 1/λ₃
11. When a p-n junction diode is subjected to reverso biasing:	(B) the barrier heught increases and the depletion region widens.
12. An alpha particle approaches a gold nucleus in Geiger-Marsden experiment with kinetic energy K. It momentarily stops at a distance d from the nucleus and reverses its direction. Then d is proportional to:	(C) 1/K
13. Assertion (A): An electron and a proton enter with the same momentum p in a magnetic field B such that p1 B. Then both describe a circular path of the same radius. Reason (R): The radius of the circular path described by the charged particle (charge q, mass m) moving in the magnetic field B is given by r = mv/qB	(A) If both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
14. Assertion (A): The magnifying power of a compound microscope is negative. Reason (R): The final image formed is erect with respect to the object.	(B) If both Assertion (A) and Reason (R) are true and Reason (R) is not the correct explanation of Assertion (A).
15. Assertion (A): Lenz's law is a consequence of the law of conservation of energy. Reason (R): There is no power loss in an ideal inductor.	(A) If both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
16. Assertion (A): Photoelectric current increases with an increase in intensity of incident radiation, for a given frequency of incident radiation and the accelerating potential. Reason (R): Increase in the intensity of incident radiation results in an increase in the number of photoelectrons emitted per second and hence an increase in the photocurrent.	D) If both Assertion (A) and Reason (R) are false.

CBSE Class 12 Physics Answer Key 2024 for QP Code: 55/4/1

Section A comprises 16 multiple-choice questions out of which 4 are based on Assertion Reasoning of 1 mark each, the answers to which for QP Code: 55/4/1 are provided here in tabular format.

Question	QP Code: 55/4/1
1. Two charges + q each are kept '2a' distance apart. A third charge - 2q is placed midway between them. The potential energy of the system is-	(C) -7q²/8πε₀a
2. Two identical small conducting balls and B₂ are given -7 pC and + 4 B₁ PC charges respectively. They are brought in contact with a third identical ball B₃ and then separated. If the final charge on each ball is -2 pC, the initial charge on B₃ was	(B) - 3pC
3. The quantum nature of light explains the observations on photoelectric effect as-	(B) the maximum kinetic energy of photoelectrons depends only on the frequency of incident radiation.
4. The radius (r_n) of nth orbit in Bohr model of hydrogen atom varies with n	(C) r_n ∝ n²
5. A straight wire is kept horizontally along east-west direction. If a steady current flows in wire from east to west, the magnetic field at a point above the wire will point towards	(C) North
6. The magnetic susceptibility for a dismagnetic material is	(A) small and negative
7. A galvanometer of resistance 100 Ω is converted into an ammeter of range (0-1 A) using a resistance of 0.1 Ω. The ammeter will show full scale deflection for a current of about	(D) 0.1 A
8. A circular loop A of radius R carries a current L. Another circular loop B of radius r (= R/20) placed concentrically in the plane of A. The magnetic flux linked with loop B is proportional to	(C) R^2/3
9. Figure shows the variation of inductive reactance X₁ of two ideal inductors of inductance L₁ and L₂ with angular frequency ω. The value of	(C) 3
10. The phase difference between electric field vec E and magnetic field vec B in an electromagnetic wave propagating along z-axis is	(A) Zero
11. A coil of N turns is placed in a magnetic field such that B is perpendicular to the plane of the coal vec R changes with time as B=B₀ cos (2πt/T) where T is time period. The magnitude of emf induced in the coil will be maximum at	(C) t = nT/2
12. In Balmer series of hydrogen atom, as the wavelength of spectral lines decreases, they appear	(B) further apart and stronger in intensity.
13. Assertion (A): Electrons are ejected from the surface of zinc when it is irradiated by yellow light. Reason (R) : Energy associated with a photon of yellow light is more than the work function of zinc.	(C) If Assertion (A) is true and Reason (R) is false.
14. Assertion (A): The temperature coefficient of resistance is positive for metals and negative for p-type semiconductors. Reason (R) : The charge carriers in metals are negatively charged, whereas the majority charge carriers in p-type semiconductors are positively charged.	(A) If both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
15. Assertion (A): When electrons drift in a conductor, it does not mean that all free electrons in the conductor are moving in the same direction. Reason (R): The drift velocity is superposed over large random velocities of electrons.	(A) If both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
16. Assertion (A) : In interference and diffraction of light, light energy reduces in one region producing a dark fringe. It increases in another region and produces a bright fringe. Reason (R): This happens because energy is not conserved in the phenomena of interference and diffraction.	(B) If both Assertion (A) and Reason (R) are true and Reason (R) is not the correct explanation of Assertion (A).

CBSE Class 12 Physics 2024: Analysis and Question Paper

The analysis and question paper for CBSE Class 12 Physics 2024 held on March 4, 2024, can be checked at the following links:

CBSE 12th Physics Exam Analysis 2024
CBSE 12th Physics Question Paper 2024

CBSE Class 12 Answer Key 2024 Links |

The question papers for the respective day-wise exams are available at the links below:

Subject	CBSE 12th Answer Key 2024 Link
Computer Science	CBSE Class 12 Computer Science Answer Key 2024
Informatics Practices	CBSE Class 12 Informatics Practices Answer Key 2024
Sociology	CBSE Class 12 Sociology Answer Key 2024
History	CBSE Class 12 History Answer Key 2024
Business Studies	CBSE Class 12 Business Studies Answer Key 2024
Accountancy	CBSE Class 12 Accountancy Answer Key 2024
Political Science	CBSE Class 12 Political Science Answer Key 2024
Biology	CBSE Class 12 Biology Answer Key 2024
Economics	CBSE Class 12 Economics Answer Key 2024
Psychology	CBSE Class 12 Psychology Answer Key 2024
Home Science	CBSE Class 12 Home Science Answer Key 2024
Physical Education	CBSE Class 12 Physical Education Answer Key 2024
Mathematics	CBSE Class 12 Mathematics Answer Key 2024
Geography	CBSE Class 12 Geography Answer Key 2024
Chemistry	CBSE Class 12 Chemistry Answer Key 2024
English Core	CBSE Class 12 English Core Answer Key 2024
Hindi	CBSE Class 12 Hindi Core Answer Key 2024
Biotechnology	CBSE Class 12 Biotechnology Answer Key 2024
Entrepreneurship	CBSE Class 12 Entrepreneurship Answer Key 2024

CBSE Class 12 2024 Weightage Subject-Wise |

Access CBSE Class 12 weightage 2024 for the upcoming papers here in the given table:

Subject	Weightage Link
Mathematics	CBSE Class 12 Mathematics Weightage 2024
Home Science	CBSE Class 12 Home Science Weightage 2024
Psychology	CBSE Class 12 Psychology Weightage 2024
Economics	CBSE Class 12 Economics Weightage 2024
Biology	CBSE Class 12 Biology Weightage 2024
Political Science	CBSE Class 12 Political Science Weightage 2024
Accountancy	CBSE Class 12 Accountancy Weightage 2024
Business Studies	CBSE Class 12 Business Studies Weightage 2024
History	CBSE Class 12 History Weightage 2024
Sociology	CBSE Class 12 Sociology Weightage 2024
Computer Science	CBSE Class 12 Computer Science Weightage 2024
Informatics Practices	CBSE Class 12 Informatics Practices Weightage 2024

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