Question

The magnetic induction at a point P which is at a distance of
4 cm from a long current carrying wire is 10–3 T. The field of
induction at a distance 12 cm from the current will be
(a) 3.33 × 10⁻⁴ T (b) 1.11 × 10⁻⁴ T
(c) 3 × 10⁻³ T (d) 9 × 10⁻³ T

Answer 1

Answer:

B2 = 3.3* 10 ⁻⁴ T

explanation:

B = μ*i/(2πr) where r is distance from wire

B1/B2 = r2/r1

B2 = 10 ⁻³ × 4/12

B2 = 0.33* 10 ⁻³ T