A circular loop has radius R and a current I flows through it. Another circular loop has a radius of 2R and a current 21 flows through it. The ratio of the magnetic fields at their centres is-
A. \(\frac { 1 }{ 4 }\)
B. 1
C. 2
D. 4
Answer:B
A circular loop has radius R and a current I flows through it. Another circular loop has a radius of 2R and a current 21 flows through it. The ratio of the magnetic fields at their centres is-
A. \(\frac { 1 }{ 4 }\) B. 1 C. 2 D. 4