The Sankalp Institute has prepared this short answer question set as a result of comprehensive research and analysis to reveal the most likely questions to be included on the JAC Class 12 Physics Exam based on the JAC Physics Exam Preparation Syllabus, current exam structure, and prior year's JAC Board Exam results. This guess question set allows students to concentrate their efforts in a finite amount of time on the questions with the greatest scoring potential, the most important and frequently asked questions.
Utilization of Very Short Answer Questions (VSQA) tests students’ ability to conceptualize their understanding of all the basic definitions, laws, principles, and key formulas that they have learned. Many times, the VSQA’s that are included as part of the JAC Board Examination come from a limited number of subjects on the syllabus, and many times, there is a lot of scoring potential in these categories. The student’s ability to provide a clear and concise answer will have a direct effect on the student’s overall score.
The guess question set consists of the Very Very Important (VVI) questions identified via a thorough trend analysis of the previous years’ JAC Board Examinations. These are the questions that have a very high probability of appearing in the upcoming JAC Board Examinations and, therefore, are necessary to study for effective exam preparation.
With the use of this guess question set, the student can eliminate unnecessary study material and reinforce their understanding of the fundamental concepts; improve speed and accuracy; and build confidence in their answer writing skills.
Chapter 1: Electric Charges and Fields
1. What are electric field lines? Mention two of its properties.2. State the principle of superposition of electric fields.
3. Define electric flux. What is its SI unit?
4. A point charge of is placed in vacuum. Find the electric flux through a spherical surface of radius 0.5 m surrounding it.
Chapter 2: Electrostatic Potential and Capacitance
5. What is an equipotential surface? Mention two properties.6. Define electric potential.
7. What is the relationship between electric field and potential?
8. Mention two factors on which capacitance of a parallel plate capacitor depends.
9. A capacitor of 4 μF is connected to a 12 V battery. Find the charge stored.
Chapter 3: Current Electricity
10. State Ohm’s law.11. Define emf of a cell. Mention two differences between emf and terminal potential difference.
12. Define drift velocity of electrons.
13. A battery of emf 10 V and internal resistance 3 Ω is connected to a resistor. If current in the circuit is 0.5 A, find the resistance of the resistor.
14. Why current decreases when internal resistance increases?
15. Explain the principle of a potentiometer. Draw the circuit diagram for comparison of emf of two primary cells.
Chapter 4: Moving Charges and Magnetism
16. Define magnetic flux.17. Define magnetic declination and dip at a place.
18. Mention one application of Fleming’s left-hand rule.
19. What is the force on a current-carrying conductor in a magnetic field?
20. A circular coil of wire consisting of 100 turns, each of radius 8.0 cm, carries a current of 0.40 A.Find the magnitude of magnetic field at the centre of the coil.
21. Derive an expression for the magnetic dipole moment of an orbital electron of an atom.
Chapter 5: Magnetism and Matter
22. Define magnetic permeability and magnetic susceptibility.23. Mention two types of magnetic materials.
24. Why does the Earth act as a magnet?
25. Why do ferromagnetic materials lose magnetism at high temperature?
Chapter 6: Electromagnetic Induction
26. What is induced emf?27. State Faraday’s law of electromagnetic induction.
28. What is Lenz’s law?
29. Mention one application of induced emf.
30. Define coefficient of self-induction and coefficient of mutual induction.
31. Derive an expression for the self-inductance of a long solenoid carrying current.
Chapter 7: Alternating Current
32. What is alternating current?33. Define RMS value of an alternating current.
34. What is half-wave rectification?
35. Define Q-factor of a coil.
36. A 60 μF capacitor is connected to a 110 V, 60 Hz AC supply. Determine the RMS value of current in the circuit.
Chapter 8: Electromagnetic Waves
37. What are electromagnetic waves? Mention two properties.38. Give one application of electromagnetic waves in communication.
Chapter 9: Ray Optics and Optical Instruments
39.Define critical angle. What are the conditions for total internal reflection?40. Define limit of resolution and resolving power of an optical instrument.
41. The far point of a myopic person is 70 cm in front of the eye. Calculate the focal length and power of the lens needed to see distant objects clearly.
42. Find an expression for the equivalent focal length for a system of two thin lenses in contact.
Mention two practical applications of ray optics experiments in lab.
Chapter 10: Wave Optics
43. Define amplitude of a wave.44. What is the time period of a wave?
45. Define angular frequency of a wave.
46. What does polarization of light mean?
47. Mention one practical experiment to demonstrate interference or diffraction.
Chapter 11: Dual Nature of Radiation and Matter
48.What are de-Broglie waves?49. Calculate the de-Broglie wavelength of a proton with momentum . Use .
50. Define threshold frequency in the photoelectric effect.
Chapter 12: Atoms
51. What is an alpha particle?52. Define mass defect and nuclear binding energy.
53. What is nuclear fission? Give an example.
54. What is nuclear fusion? Give an example.
55. What is Rutherford’s nuclear model of atom?
Chapter 13: Nuclei
56. Mention two applications each of X-rays and infra-red radiations.Chapter 14: Semiconductor Electronics
57. What is a pn junction diode? Mention one application.58. What is LED? Mention two of its applications.
59. Why is the base region of a transistor thin and lightly doped?
60. Mention one practical application of semiconductor devices in lab experiments.
Chapter 15: Communication Systems
61. Why are sky waves not used for transmitting TV signals?62. What are microwaves? Mention two applications.
63. What is a cyclotron? Mention one application.
64. What is a magnetron? Mention one application.
Chapter 16: Sources of Energy (Optional)
65. What is a solar cell? Mention two of its applications.Chapter 17: Practical / Miscellaneous Integrated
66. State and explain the principle of quantization of 67. charge.68. Why is the core of a transformer laminated?
69. Define velocity of light in a medium.
70. Define specific charge of a particle.
Numericals
1. A small oil drop carries a charge of 6.4 × 10−19 C.
(a) Find the number of excess electrons on the drop.
(b) Show that the charge on the drop is quantized.
(e = 1.6 × 10−19 C)
2. A battery of emf 10 V and internal resistance 2 Ω is connected to an external resistor. If the current in the circuit is 2 A, calculate the resistance of the external resistor.
3. Two point charges +4 μC and −2 μC are placed at a distance of 20 cm in air. Calculate the electric field intensity at the midpoint of the line joining the two charges.
4. A parallel plate capacitor has plate area 0.02 m2 and separation 1 mm. Calculate its capacitance.
(ε0 = 8.85 × 10−12 C2 N−1 m−2)
5. A charged particle of charge 1.6 × 10−19 C enters a uniform magnetic field of strength 0.5 T with a velocity of 2 × 106 m/s perpendicular to the field. Calculate the magnetic force acting on the particle.
6. The magnetic flux linked with a coil changes from 0.02 Wb to zero in 0.01 s. Calculate the induced emf produced in the coil.
7. An alternating current has a peak value of 10 A. Calculate its rms value.
8. The refractive index of glass is 1.5. Calculate the critical angle for the glass–air interface.
(sin C = 1/μ)
9. Calculate the de-Broglie wavelength of an electron accelerated through a potential difference of 150 V.
(h = 6.6 × 10−34 Js, m = 9.1 × 10−31 kg)
10. The mass defect of a nucleus is 0.03 amu. Calculate the binding energy of the nucleus.
(1 amu = 931 MeV)
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