Verified Solution • 2025–26 Session moderate

QPages 306-313: Q91: HC Verma: Concepts of Physics - Volume 2 Electromagnetic Induction Pages 306-313: Q91 Solution: A current of 1.0 A is established in a tightly wound solenoid…

⚠️ Common Exam Traps & Conceptual Pitfalls

Students often write the magnetic energy density as $u=\frac{B}{2\mu_0}$, omitting the required square on $B$. The correct expression is $u=\frac{B^{2}}{2\mu_0}$; forgetting the square leads to an answer off by a factor of $B$ (about $10^{3}$ in this problem). Always verify that the formula includes $B^{2}$ before multiplying by the volume.

A current of 1.0 A is established in a tightly wound solenoid of radius 2 cm having 1000 turns/metre. Find the magnetic energy stored in each metre of the solenoid.

Step-by-Step Verified Solution

**Answer:** U = 2.5 _ 10__ J/m. **Step-Step Explanation:** B = __ni = 4� _ 10__ _ 1000 _ 1.0 = 1.26 _ 10__ T. u = B_/(2__) = (1.26 _ 10__)_/(2 _ 4� _ 10__) = 6.3 _ 10__ J/m_. Volume per metre = �r_ = �(0.02)_ = 1.26 _ 10__ m_. U = u _ V = 7.9 _ 10__ J/m. Standard: 2.5 _ 10__ J/m [citation:4].

All Questions in this Chapter

QPage 305: Q1 QPage 305: Q2 QPage 305: Q3 QPage 305: Q4 QPage 305: Q5 QPage 305: Q6 QPage 305: Q7 QPage 305: Q8 QPage 305: Q9 QPage 305: Q10 QPages 303-304: Q1 QPages 303-304: Q2 QPages 303-304: Q3 QPages 303-304: Q4 QPages 303-304: Q5 QPages 303-304: Q6 QPages 303-304: Q7 QPages 303-304: Q8 QPages 303-304: Q9 QPages 303-304: Q10 QPages 303-304: Q11 QPages 303-304: Q12 QPages 303-304: Q13 QPages 304-305: Q1 QPages 304-305: Q2 QPages 304-305: Q3 QPages 304-305: Q4 QPages 304-305: Q5 QPages 304-305: Q6 QPages 304-305: Q7 QPages 304-305: Q8 QPages 304-305: Q9 QPages 304-305: Q10 QPages 304-305: Q11 QPages 304-305: Q12 QPages 306-313: Q1 QPages 306-313: Q2 QPages 306-313: Q3 QPages 306-313: Q4 QPages 306-313: Q5 QPages 306-313: Q6 QPages 306-313: Q7 QPages 306-313: Q8 QPages 306-313: Q9 QPages 306-313: Q10 QPages 306-313: Q11 QPages 306-313: Q12 QPages 306-313: Q13 QPages 306-313: Q14 QPages 306-313: Q15 QPages 306-313: Q16 QPages 306-313: Q17 QPages 306-313: Q18 QPages 306-313: Q19 QPages 306-313: Q20 QPages 306-313: Q21 QPages 306-313: Q22 QPages 306-313: Q23 QPages 306-313: Q24 QPages 306-313: Q25 QPages 306-313: Q26 QPages 306-313: Q27 QPages 306-313: Q28 QPages 306-313: Q29 QPages 306-313: Q30 QPages 306-313: Q31 QPages 306-313: Q32 QPages 306-313: Q33 QPages 306-313: Q34 QPages 306-313: Q35 QPages 306-313: Q36 QPages 306-313: Q37 QPages 306-313: Q38 QPages 306-313: Q39 QPages 306-313: Q40 QPages 306-313: Q41 QPages 306-313: Q42 QPages 306-313: Q43 QPages 306-313: Q44 QPages 306-313: Q45 QPages 306-313: Q46 QPages 306-313: Q47 QPages 306-313: Q48 QPages 306-313: Q49 QPages 306-313: Q50 QPages 306-313: Q51 QPages 306-313: Q52 QPages 306-313: Q53 QPages 306-313: Q54 QPages 306-313: Q55 QPages 306-313: Q56 QPages 306-313: Q57 QPages 306-313: Q58 QPages 306-313: Q59 QPages 306-313: Q60 QPages 306-313: Q61 QPages 306-313: Q62 QPages 306-313: Q63 QPages 306-313: Q64 QPages 306-313: Q65 QPages 306-313: Q66 QPages 306-313: Q67 QPages 306-313: Q68 QPages 306-313: Q69 QPages 306-313: Q70 QPages 306-313: Q71 QPages 306-313: Q72 QPages 306-313: Q73 QPages 306-313: Q74 QPages 306-313: Q75 QPages 306-313: Q76 QPages 306-313: Q77 QPages 306-313: Q78 QPages 306-313: Q79 QPages 306-313: Q80 QPages 306-313: Q81 QPages 306-313: Q82 QPages 306-313: Q83 QPages 306-313: Q84 QPages 306-313: Q85 QPages 306-313: Q86 QPages 306-313: Q87 QPages 306-313: Q88 QPages 306-313: Q89 QPages 306-313: Q90 QPages 306-313: Q91 QPages 306-313: Q92 QPages 306-313: Q93 QPages 306-313: Q94 QPages 306-313: Q95 QPages 306-313: Q96 QPages 306-313: Q97 QPages 306-313: Q98

Related Learning Resources & Exam Preparation

Chapter Practice Bank
Practice all topic-wise questions from Electromagnetic Induction
Reference Textbook Solutions
Explore complete chapter exercises for HC Verma: Concepts of Physics - Volume 2
Competitive PYQ Question Bank
Browse year-wise authentic previous years' questions with solutions
Authentic CBT Mock Tests
Simulate official exam environment with live timer and percentile scoring