Verified Solution • 2025–26 Session moderate

QPages 249-253: Q3: HC Verma: Concepts of Physics - Volume 2 Magnetic Field Due to a Current Pages 249-253: Q3 Solution: A copper wire of diameter 1.6 mm carries a current of 20 A.…

⚠️ Common Exam Traps & Conceptual Pitfalls

Students frequently substitute the given diameter ($1.6$ mm) directly into the formula $B = \frac{\mu_0 I}{2\pi r}$ without halving it to find the radius, resulting in an answer that is exactly half the correct value. Always verify that the linear dimension used in the denominator corresponds to the radial distance from the axis, not the full width of the conductor.

A copper wire of diameter 1.6 mm carries a current of 20 A. Find the maximum magnitude of the magnetic field B⃗\vec{B} due to this current.

Step-by-Step Verified Solution

**Answer:** Bmax=5×10−3B_{max} = 5 \times 10^{-3} T. **Step-by-Step Explanation:** i=20i = 20 A, r=0.8r = 0.8 mm =8×10−4= 8 \times 10^{-4} m. B=μ0i2πr=4π×10−7×202π×8×10−4=5×10−3B = \frac{\mu_0 i}{2\pi r} = \frac{4\pi \times 10^{-7} \times 20}{2\pi \times 8 \times 10^{-4}} = 5 \times 10^{-3} T.

All Questions in this Chapter

QPage 248: Q1 QPage 248: Q2 QPage 248: Q3 QPage 248: Q4 QPage 248: Q5 QPage 248: Q6 QPage 248: Q7 QPage 248: Q8 QPage 248: Q9 QPage 248: Q10 QPage 248: Q11 QPage 248: Q12 QPage 249: Q1 QPage 249: Q2 QPage 249: Q3 QPage 249: Q4 QPage 249: Q5 QPage 249: Q6 QPage 249: Q7 QPages 248-249: Q1 QPages 248-249: Q2 QPages 248-249: Q3 QPages 248-249: Q4 QPages 248-249: Q5 QPages 248-249: Q6 QPages 248-249: Q7 QPages 248-249: Q8 QPages 248-249: Q9 QPages 248-249: Q10 QPages 248-249: Q11 QPages 248-249: Q12 QPages 249-253: Q1 QPages 249-253: Q2 QPages 249-253: Q3 QPages 249-253: Q4 QPages 249-253: Q5 QPages 249-253: Q6 QPages 249-253: Q7 QPages 249-253: Q8 QPages 249-253: Q9 QPages 249-253: Q10 QPages 249-253: Q11 QPages 249-253: Q12 QPages 249-253: Q13 QPages 249-253: Q14 QPages 249-253: Q15 QPages 249-253: Q16 QPages 249-253: Q17 QPages 249-253: Q18 QPages 249-253: Q19 QPages 249-253: Q20 QPages 249-253: Q21 QPages 249-253: Q22 QPages 249-253: Q23 QPages 249-253: Q24 QPages 249-253: Q25 QPages 249-253: Q26 QPages 249-253: Q27 QPages 249-253: Q28 QPages 249-253: Q29 QPages 249-253: Q30 QPages 249-253: Q31 QPages 249-253: Q32 QPages 249-253: Q33 QPages 249-253: Q34 QPages 249-253: Q35 QPages 249-253: Q36 QPages 249-253: Q37 QPages 249-253: Q38 QPages 249-253: Q39 QPages 249-253: Q40 QPages 249-253: Q41 QPages 249-253: Q42 QPages 249-253: Q43 QPages 249-253: Q44 QPages 249-253: Q45 QPages 249-253: Q46 QPages 249-253: Q47 QPages 249-253: Q48 QPages 249-253: Q49 QPages 249-253: Q50 QPages 249-253: Q51 QPages 249-253: Q52 QPages 249-253: Q53 QPages 249-253: Q54 QPages 249-253: Q55 QPages 249-253: Q56 QPages 249-253: Q57 QPages 249-253: Q58 QPages 249-253: Q59 QPages 249-253: Q60 QPages 249-253: Q61

Related Learning Resources & Exam Preparation

Chapter Practice Bank
Practice all topic-wise questions from Magnetic Field Due to a Current
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