BITSAT 2015
- Exam
- BITSAT
- Year
- 2015
- Subject
- Physics
- Chapter
- Magnetic Effects of Current
BITSAT 2015 · Physics · Magnetic Effects of Current
A long straight wire along the Z -axis carries a current I in the...
A long straight wire along the -axis carries a current I in the negative -direction. The magnetic vector field at a point having coordinates in the plane is
Options
- A\frac{\mu_{0} I(y \hat{i}-x \hat{j})}{2 \pi\left(x^{2}+y^{2}\right)}
- B\frac{\mu_{0} I(x \hat{i}+y \hat{j})}{2 \pi\left(x^{2}+y^{2}\right)}
- C\frac{\mu_{0} I(x \hat{j}-y \hat{i})}{2 \pi\left(x^{2}+y^{2}\right)}
- D\frac{\mu_{0} I(x \hat{i}-y \hat{j})}{2 \pi\left(x^{2}+y^{2}\right)}
Correct answer
A. \frac{\mu_{0} I(y \hat{i}-x \hat{j})}{2 \pi\left(x^{2}+y^{2}\right)}
Step-by-step solution
The wire carries a current in the negative -direction. We have to consider the magnetic vector field at in the plane. 
Magnetic field is perpendicular to \quad $\vec{B}=\frac{\mu_{0} I(y \hat{i}-x \hat{j})}{2 \pi \left(x^{2}+y^{2}\right)}
Magnetic field is perpendicular to \quad $\vec{B}=\frac{\mu_{0} I(y \hat{i}-x \hat{j})}{2 \pi \left(x^{2}+y^{2}\right)}