Very long solenoid: Ampère’s law with loop abcdबहुत लंबी परिनालिका: लूप abcd के साथ ऐम्पियर नियमVery long solenoid: Ampère’s law with loop abcd

NCERT Fig 4.16 · Class 12 Physics · Chapter 4 · interactive diagram

Parts and what they mean

• Closely wound turns, n per metre (सघन फेरे, n प्रति मीटर) — ⊙ at the top, ⊗ at the bottom: the field inside points to the right.
• Uniform field inside (अंदर एकसमान क्षेत्र) — Parallel to the axis everywhere inside.
• Field outside ≈ 0 (बाहर क्षेत्र ≈ 0) — For a very long solenoid the outside field is negligible.
• Rectangular Amperian loop abcd (आयताकार ऐम्पियरी लूप abcd) — ab is inside, along B. bc and da are perpendicular to B inside (B·dl = 0) and B = 0 outside. cd is outside (B = 0).
• Length h of side ab (भुजा ab की लंबाई h) — Only ab contributes: ∮B·dl = Bh. Turns enclosed = nh.

Original diagram drawn by Simple Learning Hub, based on NCERT Fig 4.16. Report a mistake