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Physics Answer Key 2024
The Central Board of Secondary Education has conducted the Class 12 Physics Exam on 4th March 2024. Physics is regarded as one of the most changeling subjects due to its various formulas and long calculations. After taking the exam, students are anxiously looking for the CBSE Class 12 Physics Answer Key 2024. To solve this problem, the Adda247 Experience faculty provides you with an unofficial Class 12 Physics Answer Key 2024 of all sets along with a detailed explanation. Stay tuned to get the answer key of Class 12 Physics at the earliest.
Check: CBSE Class 12 Maths Answer key 2024
Class 12 Physics Answer Key 2024
Using the Class 12 Physics Answer Key 2024, students may compare their answers to all of the questions they attempted on the exam and forecast their grades. Our experts are ready to provide Physics Class 12 Answer Key 2024 for students, so they do not need to rush to other websites. Students can bookmark this page and check it regularly because we provide Class 12 Physics answer key 2024 for all sets before anyone else.
Physics 2024 Answer Key: Overview
The CBSE Class 12th Physics board exam 2024 is conducted in offline mode, i.e., pen and paper, with questions based on the syllabus. The Class 12 Physics syllabus focuses on a basic conceptual understanding of Physics, the use of SI units, symbols, nomenclature of physical quantities, and formulations by international standards, the logical sequencing of subject matter units, and the proper placement of concepts with their linkage for better learning. Let’s take a short look at the CBSE Physics 2024 answer key.
Particulars | Details |
Exam Conducting Body |
Central Board of Secondary Education (CBSE)
|
Name of Examination |
CBSE Class 12 Board Examination 2024
|
Subject | Physics |
Mode of Exam | Offline |
Exam Duration | 3 Hours |
Medium of Exam | English / Hindi |
Type of Questions |
MCQs, Short and Long Answer Type Questions
|
Theory Marks | 70 |
Practical Marks | 30 |
Total Marks | 100 |
Passing Marks | 33% in aggregate |
Class 12 Physics Answer Key 2024: Marking Scheme
When analyzing the class 12 Physics Answer Key 2024, you must understand the marking scheme. The CBSE Class 12 Physics Board Paper 2024 consists of 70 marks and lasts three hours. Students have an additional 15 minutes to review the question paper. The CBSE Class 12 Physics exam comprises of 32 questions separated into five sections: Section A, Section B, Section C, Section D, and Section E. The table below shows the distribution of marks in each section.
Sections | Number of questions | Marks Allotted |
Section-A | 16 (12 MCQs and 4 Assertion Reasoning) | 1 x 16 = 16 |
Section-B | 5 Questions | 5 x 2 = 10 |
Section-C | 7 Questions | 7 x 3 = 21 |
Section-D | 2 Case Study-Based Questions | 2 x 4 = 8 |
Section-E | 3 Long Answer Questions | 3 x 5 = 15 |
CBSE Class 12 Physics Answer Key 2024 Set 1
The CBSE Class 12 Physics Answer Key 2024 for Set 1 is shared below.
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-
Answer: (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
Answer:(B) – 3pC
3. The quantum nature of light explains the observations on the photoelectric effect as-
Answer: (B) the maximum kinetic energy of photoelectrons depends only on the frequency of incident radiation.
4. The radius (rn) of nth orbit in Bohr model of hydrogen atom varies with n
Answer: (C) rn & 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
Answer: (C) North
6. The magnetic susceptibility for a dismagnetic material is
Answer: (A) small and negative
7. A galvanometer of resistance 100 2 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
Answer: (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
Answer: (C) R2/3
9. Figure shows the variation of inductive reactance X₁ of two ideal inductors of inductance L₁ and L₂ with angular frequency w. The value of
Answer: (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
Answer: (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
Answer: (C) t = nT/2
12. In Balmer series of hydrogen atom, as the wavelength of spectral lines decreases, they appear
Answer: (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.
Answer:(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.
Answer: (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.
Answer:(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.
Answer: (B) If both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
Physics Set 3 Answer Key 2024
Physics Set 3 Answer Key 2024 for Question QP Code: -55/2/3
The CBSE Class 12 Physics Set 3 Answer Key 2024 is shared below.
Section A
(A) √3
(B) 1 / √3
(C) 3
(D) 1/ 3
Answer: (D) 1/ 3
2. Electrons drift with speed va in a conductor with potential difference V across its ends. If V is reduced to 2 their drift speed will become :
(A) Vd/ 2
(C) 2 vd
(B) vd
(D) 4 vd
Answer: (A) Vd/ 2
3. The emf induced in a coil rotating in a magnetic field does not depend upon the following:
(A) Area of the coil
(B) Resistance of the coil
(C) Number of turns in the coil
(D) Angular speed of rotation of the coil
Answer: (B) Resistance of the coil
4. A circular coil of radius 10 cm is placed in a magnetic field B = (1.01 +0.5 j) mT such that the outward unit vector normal to the surface of the coil is (0.61 +0.8). The magnetic flux linked with the coil is:
(A) 0.314 µWb
(B) 3.14 µWb
(C) 31.4 µWb
(D) 1.256 µWb
Answer:
5. Which of the following quantity/quantities remains same in primary and secondary coils of an ideal transformer?
Current, Voltage, Power, Magnetic flux
(A) Current only
(B) Voltage only
(C) Power only
(D) Magnetic flux and Power both
Answer: (D) Magnetic flux and Power both
6. In an ac circuit, the instantaneous values of current (in A) and voltage (in V) are I = 5 sin ot and E = 200 cos (ot+) respectively. The phase 3 difference between voltage and current at any instant is:
(A) 5π/ 6
(C) 5π/ 2
(B) 5π/ 4
(D) 3π/ 2
Answer: (A) 5π/ 6
7. In four regions I, II, III and IV, the magnetic field is given by:
I. By = Bo sin kz
II. By = Bo cos kz
III. By = Bo sin (kz – wt)
IV. By = Bo sin kz + Bo cos kz
The electromagnetic wave will exist in the region :
(A) IV
(B) I
(C) III
(D) II
Answer: (C) III
8. The momentum (in SI units) associated with a photon of energy 1.5 eV is:
(A) 4 x 10-27
(B) 8 × 10-28
(C) 2 × 10-30
(D) 6 × 10-29
Answer:
9. An n-type semiconducting Si is obtained by doping intrinsic Si with :
(A) Al
(B) B
(C) P
(D) In
Answer: (C) P
10.
Answer:
11. When a p-n junction diode is subjected to reverse biasing:
(A) the barrier height decreases and the depletion region widens.
(B) the barrier height increases and the depletion region widens.
(C) the barrier height decreases and the depletion region shrinks.
(D) the barrier height increases and the depletion region shrinks.
Answer: (B) the barrier height 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:
(A) 1/ √k
(B) √k
(D) K
(C) 1/ K
Answer: (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 Bis given by r = mv/ qB
Answer: (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.
Answer: (C)
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.
Answer: (B)
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.
Answer: (A)
SECTION B
17. An electric field E is maintained in a wire of length ‘l’ and area of A cross-section ‘a’. Derive the relation between the current density ‘o’ in the wire and the electric field E.
18. How does the energy gap of an intrinsic semiconductor effectively change when doped with a (a) trivalent impurity, and (b) pentavalent impurity? Justify your answer in each case.
19. (a) Two waves, each of amplitude ‘a’ and frequency ‘w’ emanating from two coherent sources of light superpose at a point. If the phase difference between the two waves is o, obtain an expression for the resultant intensity at that point.
OR
(b) What is the effect on the interference pattern in Young’s double-slit experiment when (i) the source slit is moved closer to the plane of the slits, and (ii) the separation between the two slits is increased? Justify your answers.
20. In Bohr model of hydrogen atom, find the ratio of period of revolution of the electron in the orbit n = 2 to that in the orbit n = 1.
21. A 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 refractive index 1.65. What will be the nature of the lens ?
Physics Answer Key 2024 Set 2
Q.P. Code 55/5/2
Section A
1. A 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 one. The internal resistance of the battery is:
A. 2Ω
B. 1.2Ω
C. 1Ω
D. 0.5Ω
Answer: D. 0.5Ω
2. A particle of mass m and charge q describes a circular path of radius R in a magnetic field. If its mass and charge were 2 m and q/2 respectively, the radius of its path would be:
A. R/4
B. R/2
C. 2R
D. 4R
Answer: C. 2R
3. Which of the following pairs is that of paramagnetic materials?
(A) Copper and Aluminium
(B) Sodium and Calcium
(C) Lead and Iron
(D) Nickel and Cobalt
Answer: (D) Nickel and Cobalt
4. A galvanometer of resistance 50 Ω is converted into a voltmeter of range (0 – 2V) using a resistor of 1.0 kΩ. If it is to be converted into a voltmeter of range (0 – 10 V), the resistance required will be
(A) 4.8 kΩ
(B) 5.0 kΩ
(C) 5.2 kΩ
(D) 5.4 kΩ
Answer: (C) 5.2 kΩ
5. Two 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 induced in the other. The mutual inductance of the two coils is
A. 0.4 mH
B. 2.5 mH
C. 10 mH
D. 2.5 H
Answer: A. 0.4 mH
6. The electromagnetic waves used to purify water are
A. Infrared rays
B. Ultraviolet rays
C. X-rays
D. Gamma rays
Answer: B. Ultraviolet rays
7. The focal lengths of the objective and the eyepiece of a compound microscope are 1 cm and 2 cm respectively. If the tube length of the microscope is 10 cm, the magnification obtained by the microscope for most suitable viewing by relaxed eye is:
(A) 250
(B) 200
(C) 150
(D) 125
8. The variation of the stopping potential (Vo) with the frequency (u) of the incident radiation for four metals A, B, C and D is shown in the figure. For the same frequency of incident radiation producing photo-electrons in all metals, the kinetic energy of photo-electrons will be maximum for metal
(A) A
(B) B
(C) C
(D) D
Answer:
9. The energy of an electron in the ground state of hydrogen atom is -13.6 eV. The kinetic and potential energy of the electron in the first excited state will be
(A) -13.6 eV, 27.2 eV
(B) -6.8 eV, 13,6 eV
(C) -3.4 eV, -6.8 eV
(D) 6.8 eV, -3.4 eV
Answer:
10. A Young’s double-slit experimental set up is kept in a medium of refractive index (4/3). Which maximum in this case will coincide with the 6th maximum obtained if the medium is replaced by air
(A) 4th
(B) 6th
(C) 8th
(D) 10th
11. The potential energy between two nucleons inside a nucleus is minimum at a distance of about
(A) 0.8 fm
(B) 1.6 fm
(C) 2.0 fm
(D) 2.8 fm
12. A pure Si crystal having 5 x 1028 atoms m³ is dopped with 1 ppm concentration of antimony. If the concentration of holes in the doped crystal is found to be 4.5 x 109 m-3, the concentration (in m³) of intrinsic charge carriers in Si crystal is about
(A) 1.2 × 1015
(C) 3.0 x 1015
(B) 1.5 x 1016
(D) 2.0 × 1016
Class 12 Physics Board Paper 2024 PDF Download
Here we have provided the CBSE Class 12 Physics Question Paper 2024 PDF of all sets in the table below. Candidates may download Class 12 Physics Question Papers and analyze the Class 12 Physics Answer key to calculate their expected scores.
CBSE Class 12 Physics Board Question Paper 2024 Pdf Download | |
CBSE 12 Physics Question Papers 2024- Set 1 | Download Now |
CBSE 12 Physics Question Papers 2024- Set 2 | Download Now |
CBSE 12 Physics Question Papers 2024- Set 3 | Download Now |
Class 12 Physics Exam Analysis 2024
The Class 12 Physics exam concluded at 1:30 p.m. After the exam, students can now review the CBSE Class 12 Physics Exam Analysis 2024. In CBSE Class12 Physics Exam Analysis 2024, we will evaluate the question paper based on errors, out-of-syllabus questions, and the Physics question paper’s difficulty level. The Section-wise Physics paper analysis will be shared given below.
Parameter |
CBSE Class 12 Physics Exam Analysis
|
Overall difficulty level of the paper | Moderate Level |
Difficulty level of Section A | Easy to Moderate |
Difficulty level of Section B | Moderate |
Difficulty level of Section C | Moderate to Tough |
Difficulty level of Section D | Moderate to Tough |
Difficulty level of Section E | Moderate to Tough |
Overall expected a good score | 60+ |
Which section was the lengthiest? | Section E |
Class 12 Physics Paper Analysis 2024: Students’ Reaction
After the exam, we spoke with the students who took it. According to the students, The physics exam was moderate in difficulty level. The exam elicited a variety of views, although most students thought it was well-balanced. The physics exam is always challenging because of the subject’s conceptual nature. Check out what students say about the paper.
- The Class 12 Physics Board paper 2023 was moderate in difficulty level.
- The most scoring section of the exam was section A, which consisted of MCQs
- The pattern of the question paper was identical to the sample paper issued by the board.
- Students studied diligently but still struggled to answer some questions. The numerical difficulties were very tricky. They did their best to remember all of the formulas but were confused during the exam.
- The paper’s derivations and practical issues were the most engaging sections for Students.
Class 12 Physics Board Paper Analysis 2024: Experts’ Reaction
According to the expert analysis, “the CBSE Class 12 Physics paper today was well-balanced and adhered to the syllabus.” It had an excellent mix of theoretical and application-based questions, allowing candidates to demonstrate their comprehension of ideas and problem-solving abilities. The level of difficulty appeared to be moderate, and the majority of the questions had clear directions.
Physics Answer key Class 12 2024 All Sets Mixed Question Answer
As the CBSE Class 12 Physics Exam 2024 is over, we post the detailed, 100% authentic CBSE Class 12 Physics Answer key 2024 for all sets as soon as feasible. Our in-house experts are continuously evaluating the physics answer key of section A in a detailed manner. Stay connected to us.
Q. Two charges q1 and q2 are placed at the centres of two spherical conducting shells of radius r1 and r2 respectively. The shells are arranged such that their centres are d [ >(r1 + r2)] distance apart. The force on q2 due to q1 is:
Q2. An electron enters a uniform magnetic field with speed v. It describes a semicircular path and comes out of the field. The final speed of the electron is
a) zero
b) v
c) v/2
d) 2v
Q. The magnetic field lines near a substance are as shown in the figure. The substance is:
a) Copper
b) Iron
c) Sodium
d) Aluminium
Answer- a) Copper
Q. The figure shows the variation of current (I) with time (t) in four devices P, Q, R, and S. The device in which an alternating current flows is
a) P
b) Q
c) R
d) S
Answer- d) S
Q. The electromagnetic waves used in radar system are-
a) Infrared waves
b) Ultraviolet rays
c) Microwaves
d) X-rays
Answer- c)Microwaves
Q. A straight conducting rod of length I and mass m is suspended in a horizontal plane by a pair of flexible strings in a magnetic field of magnitude B. To remove the tension in the supporting strings, the magnitude of the current in the wire is
(a) mgB/l
(b) mgl/B
(c) mg/lB
(d) lB/mg
Answer- (c)
Q. A constant current is flowing through a solenoid. An iron rod is inserted in the solenoid along its axis. Which of the following quantities will not increase?
(a) The magnetic field at the centre
(b) The magnetic flux linked with the solenoid
(c) The rate of heating
(d) The self-inductance of the solenoid
Answer- (c)
Q. A circuit is connected to an ac source of variable frequency. As the frequency of the source is increased, the current first increases and then decreases. Which of the following combinations of elements is likely to comprise the circuit ?
(a) L, C and R
(b) L and C
(c) Land R
(d) R and C
Answer- (a)
Q. If n, e, t and m have their usual meanings, then the resistance of a wire of length l and cross-sectional area A is given by –
Answer- (b)
Q. A proton and an alpha particle move in circular orbits in a uniform magnetic field. Their speeds are in the ratio of 9:4. The ratio of radii of their circular orbits (rp/ralpha) is
(a) 3/4
(b) 4/3
(c) 8/9
(d) 9/8
Answer- (d)
Q. A coil of area 100 cm2 is kept at an angle of 30° with a magnetic field of 10-1 T. The magnetic field is reduced to zero in 10-4 s. The induced emf in the coil is –
(a) 5/3 v
(b) 5073 V
(c) 5.0 V
(d) 50.0 V
Answer- (a)
Q. A 15 2 resistor, an 80 mH inductor and a capacitor of capacitance Care connected in series with a 50 Hz ac source. If the source voltage and current in the circuit are in phase, then the value of capacitance is
(a) 100 uF
(b) 127 uF
(c) 142 uF
(d) 160 uF
Answer- (b)
Q. Four objects W, X, Y and Z, each with charge +q are held fixed at four points of a square of side d as shown in the figure. Objects X and Z are on the midpoints of the sides of the square. The electrostatic force exerted by object W on object X is F. Then the magnitude of the force exerted by object W on Z is
(a) F/7
(b) F/5
(c) F/3
(d) F/2
Answer- (b)
Q. Two sources of equal emf are connected in series. This combination is, in turn connected to an external resistance R. The internal resistance of two sources are r, and r, (r, >r,). If the potential difference across the source of internal resistance r, is zero, then R equals to
Answer- (b) (r2-r1)
Q. Which of the following statements is correct?
(a) Magnetic field lines do not form closed loops.
(b) Magnetic field lines start from north pole and end at south pole of a magnet.
(c)The tangent at a point on a magnetic field line represents the direction of the magnetic field at that point.
(d) Two magnetic field lines may intersect each other.
Answer- (c)
Q. The equivalent resistance between A and B of the network shown in figure is
(a) 3R Ω
(b) (3/2)R Ω
(c) 2R Ω
(d) (2/3) RΩ
Answer- (c)
Q. A bar magnet has magnetic dipole moment M. Its initial position is parallel to the direction of uniform magnetic field B. In this position, the magnitudes of torque and force acting on it respectively are –
(a) 0 and MB
(b) MB and MB
(c) 0 and 0
(d) |M X B| and 0
Answer- (c)
Q. A 300 Ω resistor and a capacitor of (25/?)uF are connected in series to a 200V- 50Hz ac source. The current in the circuit is –
(a) 0.1 A
(b) 0.4 A
(c) 0.6 A
(d) 0.8 A
Answer- (b)
Q. A negatively charged object X is repelled by another charged object Y. However, an object Z is attracted to object Y. Which of the following is the most possibility for the object Z?
(a) positively charged only
(b) negatively charged only
(c) neutral or positively charged
(d) neutral or negatively charged
Answer- (c)
Q. In an experiment, three microscopic latex spheres are sprayed into a chamber and became charged with charges +3e, +5e and -3e respectively. All the three spheres came in contact simultaneously for a moment and got separated. Which one of the following are possible values for the final charge on the spheres?
(a) +5e, -4e, +5e
(b) +6e, +6e, -7e
(c) -4e, +3.5e, +5.5e
(d) +5e, -80, +7e
Answer- (b)
Q. An object has charge of 1 C and gains 5.0 x 1018 electrons. The net charge on the object becomes –
(a) – 0.80 C
(b) + 0.80 C
(c) +1.80 C
(d) +0.20 C
Answer- (d)
Q. Kirchhoff’s first rule EI = 0 and second rule EIR = 2E (where the symbols have their usual meanings) are respectively based on –
(a) conservation of momentum and conservation of charge
(b) conservation of energy, conservation of charge
(c) conservation of charge, conservation of momentum
(d) conservation of charge, conservation of energy
Answer- (d)
Q. The electric power consumed by a 220 V – 100 W bulb when operated at 110 V is
(a) 25 W
(b) 30 W
(c) 35 W
(d) 45 W
Answer- (a)
Q. Which of the following has a negative temperature coefficient of resistivity?
(a) metal
(b) metal and semiconductor
(c) semiconductor
(d) metal and alloy
Answer- (c)
Q. Two wires carrying currents I, and I. lie. one slightly above the other, in a horizontal plane as shown in figure. The region of vertically upward strongest magnetic field is
(a) I
(b) II
(c) III
(d) IV
Answer- (b)
Q. Two parallel conductors carrying current of 4.0 A and 10.0 A are placed 2.5 cm apart in vacuum. The force per unit length between them is –
(a) 6.4 x 10-5 N/m
(b) 6.4 x 10-2 N/m
(c) 4.6 x 10-4 N/m
(d) 3.2 x 10-4 N/m
Answer- (d)
Q. If an ammeter is to be used in place of a voltmeter, then we must connect with the ammeter a –
(a) low resistance in parallel
(b) low resistance in series
(c) high resistance in parallel
(d) high resistance in series
Answer- (a)
Q. The magnetic field at the centre of a current-carrying circular loop of radius R, is B1. The magnetic field at a point on its axis at a distance R from the centre of the loop is B2. Then the ratio (B1/B2) is
(a) 2√2
(b) 1/√2
(c) √2
(d) 2
Answer- (c)
Q. The self-inductance of a solenoid of 600 turns is 108 mH. The self-inductance of a coil having 500 turns with the same length, the same radius and the same medium will be
(a) 95 mH
(b) 90 mH
(c) 85 mH
(d) 75 mH
Answer- (d)
Q. The rms current in a circuit connected to a 50 Hz ac source is 15 A. The value of the current in the circuit Circuit , after the instant the current is zero, is –
(a) 15/√2 A
(b) 15√2 A
(c) √215 A
(d) 8
Answer- (a)
Q. In a circuit the phase difference between the alternating current and the source voltage is Which of the following cannot be the element(s) of the circuit?
(a) only c
(b) only L
(c) L and R
(d) L and C
Answer- (a)
Q. The electric potential V at any point (x, y, z) is given by V = 3×2 where x is in metres and V in volts. The electric field at the point (1 m, 0, 2m) is –
(a) 6 V/m along -x-axis.
(b) 6 V/m along +x-axis
(c) 1.5 V/m along –x-axis
(d) 1.5 V/m along +x-axis
Answer- (a)
Q. A variable capacitor is connected to a 200 V battery. If its capacitance is changed from 2 uF to X uF, the decrease in energy of the capacitor is 2 x 10-2 J. The value of X is –
(a) 1 uF
(b) 2uF
(c) 3 uF
(d)) 4uF
Answer- (d)
Q. A potential difference of 200 V is maintained across a conductor of resistance 100 2. The number of electrons passing through it in ls is
(a) 1.25 x 1019
(b) 2.5 x 1018
(c) 1.25 x 1018
(d) 2.5 x 1016
Answer- (a)
Q. When an alternating voltage E = Eo sin wt is applied to a circuit, a current I = Io sin (wt+?/2) flows through it. The average power dissipated in the circuit is
(a) Erms. Irms
(b) Eo Io
(c) Eo Io/√2
(d) Zero
Answer- (d)
Q. A current carrying wire kept in a uniform magnetic field, will experience a maximum force when it is
(a) perpendicular to the magnetic field
(b) parallel to the magnetic field
(c) at an angle of 45° to the magnetic field
(d) at an angle of 60° to the magnetic field
Answer- (a)
Q. The voltage across a resistor, an inductor, and a capacitor connected in series to an ac source are 20 V, 15 V and 30 V respectively. The resultant voltage in the circuit is
(a) 5 V
(b) 20 V
(c) 25 V
(d) 65 V
Answer- (c)
Q. In a dc circuit the direction of current inside the battery and outside the battery respectively are –
(a) positive to negative terminal and negative to positive terminal
(b) positive to negative terminal and positive to negative terminal
(c) negative to positive terminal and positive to negative terminal
(d) negative to positive terminal and negative to positive terminal
Answer- (c)
Q. The magnitude of electric field due to a point charge 2q, at distance r is E. Then the magnitude of electric field due to a uniformly charged thin spherical shell of radius R with total charge q at a distance – (r >> R) will be
(a) E/4
(b) 0
(c) 2E
(d) 4E
Answer- (c)
Q. The horizontal component of earth’s magnetic field at a place is 0.2 G whereas it’s total magnetic field is 0.4 G. The angle of dip at the place is
(a) 30°
(b) 45°
(c) 60°
(d) 90°
Answer- (c)
Q. The current in the primary coil of a pair of coils changes from 7 A to 3 A in 0.04 s. The mutual inductance between the two coils is 0.5 H. The induced emf in the secondary coil is –
(a) 50 V
(b) 75 V
(c) 100 V
(d) 220 V
Answer-(a)
Q. A square sheet of side ‘a’ is lying parallel to XY plane at z = a. The electric field in the region is E = cz2k. The electric flux through the sheet is
(a) a4c
(b) ⅓a3c
(c) ⅓a4c
(d) 0
Answer-(a)
Q. A + 3.0 nC charge Q is initially at rest at a distance of r; = 10 cm from a + 5.0 nC charge q fixed at the origin. The charge Q is moved away from q to a new position at r, = 15 cm. In this process work done by the field is
(a) 1.29 x 10-5 J
(b) 3.6 x 105 J
(c) -4.5 x 10-7J
(d) 4.5 x 10-7 J
Answer- (d)
Q. A car battery is charged by a 12 V supply, and energy stored in it is 7.20 x 105 J. The charge passed through the battery is –
(a) 6.0 x 104 C
(b) 5.8 x 103 J
(c) 8.64 x 106 J
(d) 1.6 x 106c
Class 12 Physics Answer Key 2024 with Solutions
Our Subject experts provided you with Live CBSE Class 12 Physics Answer Key and Paper Question paper Solutions in the below video, If you have any doubt regarding today’s exam then please feel free to comment down below.
Official CBSE Class 12 Physics Paper Answer Key
The official CBSE board website will host the online release of the CBSE Class 12 physics paper answer key. While they must wait for the official answer key, students can estimate their score using the Adda247 unofficial CBSE board Physics answer key that has been made available by Adda247 Expert Faculties.