Electro Magnetic Induction And Alternating Currents Question 539
Question: A closely wound coil of 100 turns and area of cross-section $ 1\ cm^{2} $ has a coefficient of self-induction 1 mH. The magnetic induction in the centre of the core of the coil when a current of 2A flows in it, will be [MP PET 1992]
Options:
A) $ 0.022\ Wb{{m}^{-2}} $
B) $ 0.4\ Wb\ {{m}^{-2}} $
C) $ 0.8\ Wb\ {{m}^{-2}} $
D) $ 1\ Wb\ {{m}^{-2}} $
Show Answer
Answer:
Correct Answer: A
Solution:
$ B=\frac{{\mu_{0}}Ni}{2r}=\frac{4\pi \times {{10}^{-7}}\times 100\times 2\times \sqrt{\pi }}{2\times {{10}^{-2}}} $ $ =0.022\ wb/m^{2} $
