154846 Two concentric coils of 10 turns each are placed in the same plane. Their radii are $20 \mathrm{~cm}$ and $40 \mathrm{~cm}$ and carry $0.2 \mathrm{~A}$ and $0.3 \mathrm{~A}$. current respectively in opposite directions. The magnetic induction (in tesla) at the centre is
154846 Two concentric coils of 10 turns each are placed in the same plane. Their radii are $20 \mathrm{~cm}$ and $40 \mathrm{~cm}$ and carry $0.2 \mathrm{~A}$ and $0.3 \mathrm{~A}$. current respectively in opposite directions. The magnetic induction (in tesla) at the centre is
154846 Two concentric coils of 10 turns each are placed in the same plane. Their radii are $20 \mathrm{~cm}$ and $40 \mathrm{~cm}$ and carry $0.2 \mathrm{~A}$ and $0.3 \mathrm{~A}$. current respectively in opposite directions. The magnetic induction (in tesla) at the centre is
154846 Two concentric coils of 10 turns each are placed in the same plane. Their radii are $20 \mathrm{~cm}$ and $40 \mathrm{~cm}$ and carry $0.2 \mathrm{~A}$ and $0.3 \mathrm{~A}$. current respectively in opposite directions. The magnetic induction (in tesla) at the centre is
154846 Two concentric coils of 10 turns each are placed in the same plane. Their radii are $20 \mathrm{~cm}$ and $40 \mathrm{~cm}$ and carry $0.2 \mathrm{~A}$ and $0.3 \mathrm{~A}$. current respectively in opposite directions. The magnetic induction (in tesla) at the centre is