Question

Two concentric circular coil of radius 20 cm and 30 cm carries current of 2A and 3A respectively in opposite direction then magnetic field at centre will be :-

• A. $4\pi\times10^{-7}\,T$
• B. $2\pi\times10^{-7}\,T$
• C. $2\times10^{-7}\,T$
• D. zero

Answer 1

Answer: (D)

zero

Answer 2

Answer (d) zero