Question

An electric wire in the wall of a building carries a dc current of 50
A vertically upward. What is the magnetic field due to this current
at a point P, 20 cm due north of the wire and the permeability of
free space, is T m/A.

Answer 1

Answer:

see diagram, here it is given that An electric wire in the wall of a building carries a DC current of 25 A vertically upward. let us consider a point P which is located at 10cm from electrical wire.

now, magnetic field at P due to electrical wire , B = \frac{\mu_0i}{2\pi r}

here, \mu_0 = 4π × 10^-7 N/A²

i = 25A and r = 10cm = 0.1m

so, B = 4π × 10^-7 × 25/(2π × 0.1)

= 2 × 10^-7 × 25/(0.1)

= 20 × 25 × 10^-7

= 5 × 10^-5 T

hence, magnet field due to electric wire at P is 5 × 10^-5 T

Answer 2

Answer:

see diagram, here it is given that An electric wire in the wall of a building carries a DC current of 25 A vertically upward. let us consider a point P which is located at 10cm from electrical wire.

now, magnetic field at P due to electrical wire , B = \frac{\mu_0i}{2\pi r}

2πrμ i

here, \mu_0μ

0

= 4π × 10^-7 N/A²

i = 25A and r = 10cm = 0.1m

so, B = 4π × 10^-7 × 25/(2π × 0.1)

= 2 × 10^-7 × 25/(0.1)

= 20 × 25 × 10^-7

= 5 × 10^-5 T

hence, magnet field due to electric wire at P is 5 × 10^-5 T

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