Explanation

Formula:

B=μ0​I/2πr​

Where:

• $mu_0 = 4pi times 10^{-7} , text{T·m/A}$ 

• $I = 5 , text{A}$ (current)

• $r = 2,text{cm} = 0.02,text{m}$

Substituting Values:

$$B = frac{4pi times 10^{-7} , text{T·m/A} times 5 , text{A}}{2 times 3.14 times 0.02, text{m}}$$2×3.14×0.02m​

Let’s calculate step by step:

Numerator:

$$4pi times 10^{-7} times 5 = 20pi times 10^{-7}$$

Denominator:

$$2 times 3.14 times 0.02 = 0.1256$$

Now,

$$B = frac{20pi times 10^{-7}}{0.1256}$$0.1256​

$$approx frac{62.8 times 10^{-7}}{0.1256} approx 5 times 10^{-5} , text{T}$$0.1256 ≈5×10^−5T