JEE Mains · Physics · STD 12 - Moving charges and magnetism
- JEE Mains 2024
- Hard
- MCQ
An element \(\Delta l=\Delta \mathrm{xi}\) is placed at the origin and carries a large current \(\mathrm{I}=10 \mathrm{~A}\). The magnetic field on the \(y\)-axis at a distance of \(0.5 \mathrm{~m}\) from the elements \(\Delta \mathrm{x}\) of \(1 \mathrm{~cm}\) length is _______.

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Answer & Solution
Correct Answer
(A) \(4 \times 10^{-8} \mathrm{~T}\)
Step-by-step Solution
Detailed explanation
\(\overrightarrow{\mathrm{dB}}=\frac{\mu_0 \mathrm{I}}{4 \pi} \frac{(\overrightarrow{\mathrm{d} l} \times \overrightarrow{\mathrm{r}})}{\mathrm{r}^3} \text { (Tesla) }\)
\(=\frac{10^{-7} \times 10 \times\left(\frac{1}{2} \times \frac{1}{100}\right)(+\hat{\mathrm{k}})}{\left(\frac{1}{2}\right)^3}=4 \times 10^{-8} \mathrm{~T}(+\hat{\mathrm{k}})\)
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