Physics

Problem

Two identical single-turn circular loops, P and Q, are made of the same wire. Loop P has radius

5\,\text{cm}

and carries a current of

3\,\text{A}

, while loop Q has radius

10\,\text{cm}

and carries a current of

6\,\text{A}

. What is the ratio of the magnetic field strengths at their centres,

B_P : B_Q

? a)

2:1

1:2

1:1

4:1