Question

A copper wire of diameter 1.6 mm carries a current i. The maximum magnetic field due to this wire is 5 × 10^–3 T. The value of i is-

• A. 40 A
• B. 5 A
• C. 20 A
• D. 2 A

Answer 1

Answer: (C)

20 A

Answer 2

B = $\frac { \mu _ { 0 } \mathrm { i } } { 2 \pi \mathrm { R } }$ \ R = $\frac { \mu _ { 0 } \mathrm { i } } { 2 \pi \beta }$