Question

Two circular coils made of similar wires but of radius 20 cm and 40 cm are connected in parallel. The ratio of magnetic fields at their centre is-

• A. 4 : 1
• B. 1 : 4
• C. 2 : 1
• D. 1 : 2

Answer 1

Answer: (A)

4 : 1

Answer 2

$\left( \frac { 40 } { 20 } \right) ^ { 2 }$= 4