Solution:
Solution
The dipole moment of circular loop is m
$$m_1= I.A = I. \pi R^2$$ { R = radius of the loop}
$$B_1 = \dfrac{\mu_{o}I}{2R}$$
moment becomes double, R becomes $$\sqrt{2}R$$(keeping the current constant)
$$m_2 = I. \pi(\sqrt{2}R)^2= 2. I \pi R^2= 2 m_1$$
$$B_2 = \dfrac{\mu_o I}{2 \sqrt{2}R}=\dfrac{B_1}{\sqrt{2}}$$
$$\dfrac{B_1}{B_1}= \sqrt{2}$$