Question

Equal currents i = 1 A are flowing through the wires parallel to y-axis located at x = + 1m, x = + 2 m, x = + 4 m etc. but in opposite directions as shown. The magnetic field at origin (in tesla) would be-

• A. – 1.33 × 10^–7 $\hat { \mathbf { k } }$
• B. 1.33 × 10^–7$\hat { \mathbf { k } }$
• C. 2.67 × 10^–7$\hat { \mathbf { k } }$
• D. – 2.67 × 10^–7 $\hat { \mathbf { k } }$

Answer 1

Answer: (B)

1.33 × 10^–7$\hat { \mathbf { k } }$

Answer 2

= $\left[ \left( \frac { 1 } { 1 } + \frac { 1 } { 4 } + \frac { 1 } { 16 } + \ldots \ldots . .\right) \hat { \mathrm { k } } - \left( \frac { 1 } { 2 } + \frac { 1 } { 8 } + \ldots \ldots \right) \hat { \mathrm { k } } \right]$