Answer:
Explanation:
Magnetic field due to a solenoid
B = μ₀ nI where n is no of turns per unit length and I is current
for outer layer of turns
B = μ₀ x (250 / .3) x 3
= 4π x 10⁻⁷ x (250 / .3) x 3
= 3.14 x 10⁻³ T
for inner layer of turns
B = μ₀ x (300 / .3) x 3
= 4π x 10⁻⁷ x (300 / .3) x 3
= 3.77 x 10⁻³ T
Total magnetic field
= (3.14 + 3.77 ) x 10⁻³ T
= 6.91 x 10⁻³ T .