Verified Solution • 2025–26 Session moderate

QPages 230-234: Q8: HC Verma: Concepts of Physics - Volume 2 Magnetic Field Pages 230-234: Q8 Solution: A current of 2 A enters at the corner of a square frame of side …

⚠️ Common Exam Traps & Conceptual Pitfalls

Students often incorrectly assume the full 2 A current flows through each individual side, failing to recognize that the current splits equally (1 A per branch) at the entry node due to the symmetric resistance of the square frame's two parallel paths.

A current of 2 A enters at the corner dd of a square frame abcdabcd of side 20 cm and leaves at the opposite corner bb. A magnetic field B=0.1 TB = 0.1 \text{ T} exists in the space in a direction perpendicular to the plane of the frame, as shown in the figure. Find the magnitude and direction of the magnetic forces on the four sides of the frame.

Step-by-Step Verified Solution

**Answer:** Forces on sides: Fab=Fcd=0F_{ab} = F_{cd} = 0, Fbc=Fda=0.2 NF_{bc} = F_{da} = 0.2 \text{ N}. **Step-by-Step Explanation:** The current enters at d and leaves at b. By symmetry, the currents in sides ad and dc are equal, as are those in ab and bc. The magnetic field is perpendicular to the plane. Forces on sides parallel to the field are zero. Forces on sides perpendicular to the field are F=IlBF = I l B. For sides dc and ab (length 20 cm), I=1 AI = 1 \text{ A}: F=1×0.2×0.1=0.02 NF = 1 \times 0.2 \times 0.1 = 0.02 \text{ N}.

All Questions in this Chapter

QPage 229: Q1 QPage 229: Q2 QPage 229: Q3 QPage 229: Q4 QPage 229: Q5 QPage 229: Q6 QPage 229: Q7 QPage 229: Q8 QPage 229: Q9 QPage 229: Q10 QPages 228-229: Q1 QPages 228-229: Q2 QPages 228-229: Q3 QPages 228-229: Q4 QPages 228-229: Q5 QPages 228-229: Q6 QPages 228-229: Q7 QPages 228-229: Q8 QPages 228-229: Q9 QPages 228-229: Q10 QPages 229-230: Q1 QPages 229-230: Q2 QPages 229-230: Q3 QPages 229-230: Q4 QPages 229-230: Q5 QPages 229-230: Q6 QPages 229-230: Q7 QPages 229-230: Q8 QPages 229-230: Q9 QPages 229-230: Q10 QPages 230-234: Q1 QPages 230-234: Q2 QPages 230-234: Q3 QPages 230-234: Q4 QPages 230-234: Q5 QPages 230-234: Q6 QPages 230-234: Q7 QPages 230-234: Q8 QPages 230-234: Q9 QPages 230-234: Q10 QPages 230-234: Q11 QPages 230-234: Q12 QPages 230-234: Q13 QPages 230-234: Q14 QPages 230-234: Q15 QPages 230-234: Q16 QPages 230-234: Q17 QPages 230-234: Q18 QPages 230-234: Q19 QPages 230-234: Q20 QPages 230-234: Q21 QPages 230-234: Q22 QPages 230-234: Q23 QPages 230-234: Q24 QPages 230-234: Q25 QPages 230-234: Q26 QPages 230-234: Q27 QPages 230-234: Q28 QPages 230-234: Q29 QPages 230-234: Q30 QPages 230-234: Q31 QPages 230-234: Q32 QPages 230-234: Q33 QPages 230-234: Q34 QPages 230-234: Q35 QPages 230-234: Q36 QPages 230-234: Q37 QPages 230-234: Q38 QPages 230-234: Q39 QPages 230-234: Q40 QPages 230-234: Q41 QPages 230-234: Q42 QPages 230-234: Q43 QPages 230-234: Q44 QPages 230-234: Q45 QPages 230-234: Q46 QPages 230-234: Q47 QPages 230-234: Q48 QPages 230-234: Q49 QPages 230-234: Q50 QPages 230-234: Q51 QPages 230-234: Q52 QPages 230-234: Q53 QPages 230-234: Q54 QPages 230-234: Q55 QPages 230-234: Q56 QPages 230-234: Q57 QPages 230-234: Q58 QPages 230-234: Q59 QPages 230-234: Q60 QPages 230-234: Q61

Related Learning Resources & Exam Preparation