The introduction of this guess question set has been prepared by Sankalp Institute based on a detailed analysis of the current syllabus, the present examination pattern, and question papers of previously conducted Jharkhand Academic Council (JAC) board examinations. The purpose of this guess question set is to help students appearing in the Class 12 JAC Board examinations achieve maximum success with efficient preparation in a limited time.
As an academic subject, Physics includes concepts, derivations, numerical problem-solving, and proper methods of structuring answers in the answer sheet. In the JAC Board examinations, long answer questions from certain topic areas are included in the syllabus and have been repeated on several occasions. The JAC Board examination provides students with specific “very very important” (VVI) questions on which to focus their studies. This guess question set includes only those questions that have been identified as having a high probability of being asked in future examinations.
This guess question set offers students a targeted approach to preparation, allowing them to avoid spending time on irrelevant material and making it an extremely effective study tool. Furthermore, through comprehensive study of this guess question set, students will build confidence in their answer-writing skills and develop the abilities required for productive and successful learning.
Chapter 1: Electric Charges and Fields
1. State Gauss’s law (Gauss's theorem) in electrostatics. Using this law, derive expressions for the electric field due to a uniformly charged thin spherical shell at a point(a) outside the shell and
(b) inside the shell.
2. Define electric dipole moment. Derive an expression for the electric field at a point on the equatorial (broad-side-on) position of an electric dipole.
Chapter 2: Electrostatic Potential and Capacitance
3. Define electric potential. Derive an expression for electric potential at a point due to a point charge. Also, establish the relation between electric potential and electric field.
Chapter 3: Current Electricity
4. Define drift velocity. Derive an expression for drift velocity and hence deduce Ohm’s law.Chapter 4: Moving Charges and Magnetism
5. State the principle of a moving-coil galvanometer. Describe its construction and explain its working with a neat labelled diagram.6. Explain the principle of a cyclotron. Describe its construction and working.
7. State the Biot–Savart law. Using it, derive an expression for the magnetic field at a point on the axis of a current-carrying circular coil.
8. State Ampere’s circuital law. Using it, derive an expression for the magnetic field due to a long straight current-carrying conductor.
Chapter 6: Electromagnetic Induction
9. Explain electromagnetic induction. State Faraday’s laws and derive an expression for induced emf in a conductor moving in a uniform magnetic field.10. Explain the principle of an AC generator. Describe its construction and working. Obtain the expression for the induced alternating emf.
Chapter 7: Alternating Current
11. Describe the principle, construction, and working of a transformer. Obtain the relation between primary and secondary voltages and currents.Chapter 9: Ray Optics and Optical Instruments
12. Draw a neat labelled diagram of a compound microscope showing the formation of image. Derive an expression for its magnifying power.13. For refraction through a thin lens, derive the relation
1/f = (μ2 − 1) / μ1 × ( 1/R1 − 1/R2 )
where the symbols have their usual meanings.
Chapter 10: Wave Optics
14. Explain Young’s double-slit experiment with necessary theory and obtain an expression for fringe width.15. State Huygens’ principle. Using it, explain refraction of light at a plane surface and derive Snell’s law.
Chapter 11: Dual Nature of Radiation and Matter
16. Describe the photoelectric effect. State its laws and explain them using Einstein’s photoelectric equation.
Chapter 12: Atoms
17. Explain Bohr’s atomic model. Derive expressions for the radius and energy of an electron in a hydrogen atom.