JAC Board 12th Physics Preboard Solution 2024 PDF

Website: https://www.jharedu.in https://www.youtube.com/@physicswithabhijeetsingh PRE-TEST EXAMINATION -2024 DIST.- GIRIDIH (JHARKHAND) CLASS -12TH SUB-PHY...

Website: https://www.jharedu.in https://www.youtube.com/@physicswithabhijeetsingh PRE-TEST EXAMINATION -2024 DIST.- GIRIDIH (JHARKHAND) CLASS -12TH SUB-PHYSICS F.M. - 70 MARKS TIME-3HR GENERAL INSTRUCTIONS : 1. This question paper has two parts - part-A and part- B. n rart-A is of M.C.Q type having 25 marks and part-B is of subiective type having 45 markS. ne candidate has to answer in the answer booklet which willbe provided separately. uc nel io T There are 25 multiple choice guestions having four options (A.B.C,& D). the candidate nas to write the correct option in the answer booklet.all guestions are compulsory. Each question carry one mark. There is no negative marking for wrong answer. Ed an at 5. Part-B there are three sections: section A,B &C. this part is of subjective type having very short answer, short answer and long answer type questions. 6 Gandidates are required to answer in their own words as far as practicable. Ch 7. Drawneat and clear diagram wherever necessary. e ub uT PARTA nd 1. When an electric dipole is placed in uniform electric field it experiences (a) Anet force (b) a torque (c) botha net force and torque Yo (d) neither a net force or atorque ha rk 2. Which of the following is the S.I. unit of dipole moment (a) Coulomb (b) coulomb I sec (c) coulomb-meter (d) ampere a Jh (a) coefomb (b) Couyombfsee c) Couomb-mfer (d ampere 3. Three capacitors each of capacity Care connected in parallel. Their equivalent capacitance will be (b) 3C (c) 1/3C (d)3/C (a) Cl3 (b) 3c (C ) (y (o) https://www.youtube.com/@JharkhandEducation https://www.youtube.com/@ComputerKaksha  Website: https://www.jharedu.in https://www.youtube.com/@physicswithabhijeetsingh 4. Relation between the electric field 'E' and the electric potential y' is V= dE/dx (a) E- dV/dx (b) E= dV/dx (c) V=- dEldx (d) separation between the 5. How do the capacity of a parallel plate capacitor changes when plates is decreased (d) none (a) Increases (b) decreases (c) remains n uc nel io Ed an at 6. Relation between drift velocity (V) and current density(J) is - (d) J= Veln (a) J=neV (b) J= ne/V (c) J =VIne Ch e ub Magnetic field due to a toroidal solenoid is independent of (a) lts number of turns (c) radius (d) none of these uT (b) electric current nd Yo (a) ha 8. The magnetic line of force inside a bar magnet rk (a) Are from N- pole to S- pole of the magnet (b) Are from S- pole to N- pole of the magnet (c) Depends on area of cross section of bar magnet a (d) Do not exist. Jh 9. Lenz law is based on the principle of (a) Conservation of the charge (b) Conservation of the energy https://www.youtube.com/@JharkhandEducation https://www.youtube.com/@ComputerKaksha  Website: https://www.jharedu.in https://www.youtube.com/@physicswithabhijeetsingh (c) Conservation of mass (d) Conservation of angular momentum 10. Two parallel conductors carrying current in the same direction will (a) Attract each other n (b) Repel each other (c) Neither attract nor repel uc nel io (d) None of these Ed an at (Q) (b) Ch e ub 11. The role of self inductance is equivalent to (a) Momentum (b) force (c) energy (d) inertia uT nd Yo ha 12. A transformer can work rk (a) Only for A.C (b) Only for D.C (c) Both for A.C and D.C a (d) None Jh (a le) 43. The phase difference between current and voltage in an A.Ccircuit containing inductance only is. https://www.youtube.com/@JharkhandEducation https://www.youtube.com/@ComputerKaksha  Website: https://www.jharedu.in https://www.youtube.com/@physicswithabhijeetsingh (a) 90 (b) 0 (c) 180 (d) 60 (d) 14.Which of the following electromagnetic wave is used in the treatment of cancer (a) X-ray n (b) micro wave (c) radio wave (d) gamma ray uc nel io Ed an at Ch 15. Which of the following series of hydrogen spectrum lies in the visible region of electromagnetic spectrum e (a) balmer (b) lyman (c) paschen (d) brackett ub uT nd ( alH Yo ha 16.WHremagnification of a mirroris found bbe m=1.5.the type mirror is (a) convex mirror (b) concave mirror (c) plane mirror (d) none a rk Jh for 17. The refractive index of amedium is minimum (a) red light (b) blue light (c) green light (d) violet light (e) https://www.youtube.com/@JharkhandEducation https://www.youtube.com/@ComputerKaksha  Website: https://www.jharedu.in https://www.youtube.com/@physicswithabhijeetsingh 18. which of the following (a) refraction of light phenomenon can not be explained through ray op (b) total internal reflection lc) diffractlon of light (d) dispersion of light n uc nel io 19. the length of the an (a) fo-f, astronomical telescope in normal adjustment is (b) f, * f, (c) fo+f, Ed an at (d) f, /f, Ch (a) 4) to/te e 20. huygen's wave theory of light cannot explain. ub (a) Reflection of light (b)refraction of light (c) total internal reflection (d) photoelectric effect fafsia uT nd Yo ha 21. According tode- Broglie hypothesis, the wavelength of rk matter wave is given by (a)) A=h/my (b) ^= mv/h (c) A=hmv (d) A=hv/m a Jh (b) (c) hmv orhit 92 Fthe ratio of 1s bohrlis'r,the radius of second bohr's orbit is (a) 2r (b) 4r (c) rl2 (d) we (a) 2 r (b) 4r https://www.youtube.com/@JharkhandEducation https://www.youtube.com/@ComputerKaksha  Website: https://www.jharedu.in https://www.youtube.com/@physicswithabhijeetsingh 23. If the forbidden energy gap in a substance is 1ev, (a) Conductor substance is a (b) semiconductor (c) insulator (d) superconductor (2) (C) 24. When indium is doped to silicon as impurity, the resulting material is (a) P-type semiconductor n (b) N-type semiconductor uc nel (c) Both io (d) None Ed an at (a) Ch e 25. When a reverse bias is applied to a p-n junction,it ub (a) Raises the potential barrier (b) Reduces the majority carrier current to zero (c) Lowers the potential barrier uT nd (d) None of these Yo ha (6) a rk PART-B Jh Section -A Answer any seven questions. Answer the questions inamaximum of one sentence each 26. Two equalcharges, opposite in nature separated by very small distance is caled https://www.youtube.com/@JharkhandEducation https://www.youtube.com/@ComputerKaksha  Website: https://www.jharedu.in https://www.youtube.com/@physicswithabhijeetsingh 27. Write down the formula for electric flux according to gauss's theorem. 28. What is the S.l unit for magnetic flux? 29. What is the average value of A.C. for half cycle ? n uc nel io 3U. What electromagnetic waves are used for the surgery of human eye? Ed an at slits? l hoW will the width of fringes change if distance of the screen is increased from the Ch e ub 32. Define threshold frequency. uT nd Yo 33. Write any two properties of nuclear force. ha 34. What do you mean by depletion layer? rk Section -B a Answer any six questions. Answer thequestions in a maximum of 150 words each 36=s Jh 618 Q5 Define dipole moment and write down its c.g.s. unit. An electric dipole with dipole moment 3 x10° C-m is inclined at 30° with the direction of a uniform electric field of maanitude 8 x 10° NIC. calculate the magnitude of torque acting on dipole. https://www.youtube.com/@JharkhandEducation https://www.youtube.com/@ComputerKaksha  Website: https://www.jharedu.in https://www.youtube.com/@physicswithabhijeetsingh 36. State kirchhoff's rules, Explain briefly how these rules are justified. field inside a 37. StateAmpere's circuital law. Derive an expressionfor induced magnetic solenoid. n uc nel 38. Explain self induction, Derive the expression for coefficient of self inductance and wte io down its unit. an at Ch of alternating current for half cycle. The 39. Derive an expression for average or mean value find the root mean equation for an alternating current is =32 sin (100nt + l4) A. square value of the current. e Ed ub uT experiment and concludes the Ruther nd 40. Explain Ruther ford's alpha particle scattering ford's atomic model. Yo ha -V graph for forward and reverse 41. Explain forward and reverse biasing of adiode. Draw biasing. a rk differences between p-type and n- vne 42. Explain the term Doping. Write down any two Jh semiconductor. Section -C maximum of 250 wordss egeh Answer any four questions. Answer the questions in a https://www.youtube.com/@JharkhandEducation https://www.youtube.com/@ComputerKaksha  Website: https://www.jharedu.in https://www.youtube.com/@physicswithabhijeetsingh 43. Derive an expression for the electric field at a point on axial lino of an electric dipole. 44. Explain with circuit diagram the Obtainthe parallellcombination d of identical cells. condition for maximum current in the external resistance connected with tne n combination. uc nel io Ed an at a current carrying 43. Derive an expression for the magnetic field at a point on the axis of circular coil. Also find the magnetic field at the centre of the coil. Ch e 46. Derive the lens maker's formla for athin lens: 1/f =(p-1) (1/R,-1/ Rz). ub uT nd Yo Huygen's principle. 47. Prove snell's law of refraction on the basis of ha a rk Jh https://www.youtube.com/@JharkhandEducation https://www.youtube.com/@ComputerKaksha