0.5 m लंबे एक परिनालिका (solenoid) में 400 फेरे (turns) हैं और इसमें 3 A की धारा प्रवाहित हो रही है। निर्वात की चुंबकशीलता μ0 = 4π × 10-7 T·m/A लेते हुए, परिनालिका के केंद्र पर चुंबकीय क्षेत्र का अनुमानित मान कितना है?

Consider two wire arrangements carrying equal current I: Arrangement 1 consists of a semi-circular arc of radius R and two straight infinite wire segments extending along its tangent. Arrangement 2 consists of a semi-circular arc of radius R with two radial straight wires extending to infinity. The ratio of the magnetic field at the center of the semi-circular part in Arrangement 1 to that in Arrangement 2 is:

The magnetic field produced inside a long current-carrying solenoid is: