You are doing a study of bird migration and need to determine the strength and d

Question

You are doing a study of bird migration and need to determine the strength and direction of the Earth

You are doing a study of bird migration and need to determine the strength and direction of the Earthas magnetic field B using a magnetometer (a device for measuring magnetic fields). This magnetometer consists of a long wire carrying 10.0 A of current. Assume the wire and the magnetic field are both parallel to the ground. For the two orientations of the wire shown (viewed from above), the magnitude of the force per unit length F/L is given. The orientation of the wire in Figure I is perpendicular to the orientation of the wire in Figure II b. Your research student is standing 5.00 m away from the wire. What is the strength of the magnetic field at that location due solely to the wire?

Explanation / Answer

Magnetic field at a point at a distance r due to a straight wire carrying current as shown in fig 1 is given by:

B = ( u0/ 4*pie )* ( 2 *I / r)                               ( u0/ 4 pie = 10-7)

B = 10-7 * 2 * 10 / 5 = 4 * 10-7 Tesla

Its direction will be directed inwards or anticlockwise in form of concentric circles along the wire, from Right hand thumb rule.

(b) In fig (II) dl and r will both in same direction. so angle between them = 0

From biot savart's law magnetic field at a point due to current element is given by:

dB = u0 /4 pie * ( I dl sin@ / r2 )

here @ is the angle between dl and r which is zero.

sin 0 = 0

so dB = 0

Related Questions

Navigate

• Browse (All)
• Browse Y
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.