Question

A wire placed along north south direction carries a current of $5 A$ from south to north. Find the magnetic field due to a $1 m$ piece of wire at a point $200 cm$ north east from the piece.

• A. $8.8 \times 10^{-10} T$ acting vertically downward.
• B. $4.4 \times 10^{-10} T$, acting vertically downward
• C. $2.2 \times 10^{-10} T$, acting vertically upward
• D. $1.1 \times 10^{-10} T$, acting horizontally

Answer 1

Answer: (A)

$dB =\frac{\mu_{0}}{4 \pi} \times \frac{ Id \ell \sin \theta}{ r ^{2}}$
$=\frac{10^{-7} \times 5 \times 10^{-2} \times \sin 45}{(2)^{2}}$
$dB=8.8 \times 10^{-10} T$
Acting vertically downward.