# JAC 12th Physics Important Questions 2023 Unit 3 : Magnetic Effect of Current and Magnetism

## JAC 12th Physics Important Questions 2023 [Unit 3.] Exam: झारखण्ड बोर्ड कक्षा 12th सभी विद्यार्थियों के लिए Physics Unit 3. Magnetic effect of current and magnetism Chapter 4. Moving Charges and Magnetism| Chapter 5. Magnetism and Matter के पिछले वर्षो में जो भी प्रश्न पूछे गए हैं, उनकी चर्चा हम इसमें करेंगे तो इन Important Questions को पढ़ लीजिए.

रांची: झारखंड एकेडमिक काउंसिल ( JAC Board) कक्षा JAC 12th Physics Important Question के पिछले वर्षों के सभी महत्वपूर्ण प्रश्न (important Questions) आपको यहाँ पर बताए जा रहे है, जो बोर्ड परीक्षा 2023 के लिए बहुत महत्वपूर्ण है. अगर आप इन सभी प्रश्नों को याद कर लेते हो तो अवश्य ही आप JAC Board class 12th Physics exam 2023 में अच्छे अंक प्राप्त कर सकते हो.

यदि आप ऐसे ही सभी विषयों के Chapterwise Questions उत्तर चाहते हैं तो हमारे वेबसाइट jharkhandlab.com से जुड़े रहे.

विद्यार्थी इसका उत्तर स्वयं करें। ये सारे प्रश्न आपके परीक्षा (JAC 12th Physics Important Question For Board Exams)में बार – बार पूछे जा रहे है। इसमें आपको सभी chapter का अलग-अलग पिछले 16 से 17 वर्षों के महत्वपूर्ण प्रश्न मिलेंगे। यानि 2006-2022 इसमें आपको ये भी बताया जा रहा है कि कौन से प्रश्न किस तरह से एवं कितने marks के पूछे जा रहें है।

यदि वैसे छात्र छात्राएं जो प्रश्नों के उत्तर नहीं कर पाते हैं, वो कुछ दिन प्रतीक्षा करें. आप यहाँ से Questions-answers डाउनलोड कर सकते हैं.

### JAC 12th Physics Previous Years Important Questions-

Q1. Mention the differences between the magnetic properties of soft iron and steel.(2006)
Q2. State and explain the Biot – Savart law? Derive an expression for the magnetic field at a point due to a current carrying straight wire of infinite length. (2006)

Q3. What are the magnetic elements of earth at a place? Define them. (2007, 2009)
Q4. Describe , with theory , the construction and working of a moving coil galvanometer. (2007, 2009)
Q5. What is the nature of magnetic field in a moving coil galvanometer? (2008)
Q6. Obtain an expression for the force on a moving charge in uniform magnetic field. Under what condition this force is maximum? (2008)

Q7. Describe, with theory, the construction and working of a cyclotron. (2008, 2015, 2017, 2020)

Q8. Name the physical quantity whose S.I. unit Weber. (2009)

Q9. What is meant by magnetic field and field intensity? (2010)
Q10. Show the magnitude of force experienced by a stationary charged exposed to a uniform magnetic field. (2010)
Q11. A circular coil of a diameter 0.2m has tightly wounded 100turns and carriers a current of 1A. What is the value of magnetic field strength at the center of the coil ? (2011)
Q12. What is magnetic field? State and explain Biot – Savart law? (2011)

Q13. Explain with the help of labelled diagram the principle, construction and working of a cyclotron. Show that the cyclotron frequency does not depend on the speed of particles. (2012)
Q14. What do you understand by potential energy of a magnetic dipole ? Obtain an expression for torque acting on a magnetic dipole placed in a uniform magnetic field. (2012)
Q15. According to Biot-sarvat law magnetic field at a point due to current caring element depend on distance of a point from current element as-(2013)
a. B α r
b.B α 1/r
c. B α r²
d. B α 1/r²

Q16. Using ampere circuital law, find magnetic field at a point due to very long current caring straight wire, when point is outside the wire? (2013)
Q17. Find the magnetic field due to a bar magnet at a point along its axis and perpendicular to its axis. (2013)
Q18. Find the force on a current caring conductor in a uniform magnetic field. Using it find the force between parallel current carrying wire. (2013)

Q19. What is magnetic field lines? Give any two properties of magnetic field lines. (2014)
Q20. What is Biot sarvat law? Find expression for magnetic induction at a point on the axis of current carrying coil. (2014, 2017, 2019)
Q21. What is Ampere’s circuital law? Using Ampere’s circuital law, find magnetic field at a point inside a straight current caring solenoid.(2014, 2015)

Q22. If the number of turns in a moving coil galvanometer is increases, its sensitivity(2015)
a. Increase
b. Decrease
c. Remains same
d. May increase or decrease
Q23. Derive an expression for the magnetic dipole moment of Orbital electron of an atom. (2016)
Q24. A circular coil of wire consisting of 100 turns , each of radius 8.0cm, carries a current of 0.40A. What is the magnitude of magnetic field at the centre of the coil? (2016)

Q25. Define the terms magnetic permeability and magnetic susceptibility? (2017)
Q26. Define magnetic declination and dip at a place. (2018)
Q27. Describe, with principle, the construction and working of a moving coil galvanometer. (2018)

Q28. State Ampere’s circuital law. Using this law, to find at a point inside a current caring toroid. Hence find magnetic field at a point inside a long solenoid carrying circuit. (2018)
Q29. What are paramagnetic substance? How does it magnetic susceptibility very with temperature. (2019)
Q30. Find the force acting on the current carrying conductor in uniform magnetic field. Using it find the force between two parallel current carrying conductors. (2019)

Q31. Derive an expression for a torque acting on a current carrying rectangular coil placed in a uniform magnetic field. (2020)

## Last Year 2022 Objective Questions-

Q32. An electrons enters perpendicularly to a uniform magnetic field. The path of electron will be-
a. Circular
b. Parabolic
c. Linear
d. Spiral
Q33. Q. The magnetic field ‘B’ at the centre of a current  carrying circular loop of radius ‘r’ is –
a. B is directly proportional to r
b. B is inversely proportional to r
c. B is directly proportional to r²
d. B is inversely proportional to r²

Q34. A moving charged particle experiences no force while through uniform magnetic field –
a. If charged particle moves perpendicular to the magnetic field
b. if charged particle moves parallel to the magnetic field
c. If charged particle moves at an angle  of 45° to the magnetic field
d. If charged particle moves at an angle  of 60° to the magnetic field

Q35. Magnetic field due to a toroidal solenoid in independent of –
a. Its number of turns
b. electric current
d. None of these
Q36. S.I. unit of magnetic field is-
a. Gauss
b. Tesla
c. weber
d. None of these
Q37. Two parallel conductors carrying current im the same direction will –
a. attract each other
b. repel each other
c. neither attract nor repel
d. none of these

Q38. A current carrying loop is placed in a uniform magnetic field. The torque acting on it does not depend upon
a. area of loop
b. value of current
c. magnetic field
d. none of these
Q.39. Magnetic elements of earth are
a. iron , nickel and cobalt
b. aluminium, silver and gold
c. three quantities that describe magnetic behaviour of the earth
d. none of these
Q40. According to Ampere’s circuital law – 