Question

Electric wires in the wall of a building carries a dc current of 25 ampere vertically upward what is the magnetic field due to this current and a point which is 10cm to the right of the wire

Answer 1

Answer:

Explanation:

Use the formula for finding mag. field at a distance r from it i.e.

$\frac{ \mu I}{4 \pi D} (sin\alpha + sin\beta ) =B$

Answer 2

Answer:

5 × 10^-5 T

Explanation:

MAGNETIC FIELD DUE TO A STRAIGHT WIRE :

Let the magnetic field due to a straight wire be B.

The magnetic field B at a point near it is directly proportional to the current I in Amperes in the wire and inversely proportional to the distance r from the wire.

This relationship can be summarized as follows :

B ~ I/r

B = MoI / 2pie × r

Mo = the permeability of free space.

Mo = 4pie × 10^-7 T. m/A

From the question :

r = 10/100 = 0.1 meters

I = 25 A

Doing the substitution we have :

[(4pie × 10^-7 T. m/A)(25A)] / [(2pie × 0.10m)] = 5 × 10^-5 T

= 5.0 × 10^-5 T