Solveeit Logo
Login

Question

Physics Question on Moving charges and magnetism

A long straight wire is carrying a current of 12 A12\,A. The magnetic field at a distance of 8 cm 8\,cm is (μ0=4π×10−7 N/A2)(\mu _{0}=4\pi \times 10^{-7}\,N/A^{2})

A

2×10−4Wb/m2 2\times 10^{-4}Wb/m^{2}

B

3×10−5Wb/m2 3\times 10^{-5}Wb/m^{2}

C

4×10−4Wb/m2 4\times 10^{-4}Wb/m^{2}

D

4×10−5Wb/m2 4\times 10^{-5} Wb/m^{2}

Answer

3×10−5Wb/m2 3\times 10^{-5}Wb/m^{2}

Explanation

Solution

Magnetic field B=μ0I2πrB=\frac{\mu_{0} I}{2 \pi r}
Given. μ=4π×10−7N/A2\mu=4 \pi \times 10^{-7} N / A^{2},
r=8 cm=8×10−2mr=8\, cm =8 \times 10^{-2} m
I=12 AI=12\, A
B=4π×10−72π×128×10−2B=\frac{4 \pi \times 10^{-7}}{2 \pi} \times \frac{12}{8 \times 10^{-2}}
⇒B=3×10−5Wb/m2\Rightarrow B=3 \times 10^{-5} Wb / m ^{2}