Magnetic Effects Of Current Question 115
Question: The earth?s magnetic field at a given point is $ 0.5\times {{10}^{-5}}Wb\text{-}{{m}^{-2}} $ . This field is to be annulled by magnetic induction at the center of a circular conducting loop of radius 5.0cm. The current required to be flown in the loop is nearly [AIIMS 2003]
Options:
A) 0.2 A
B) 0.4A
C) 4A
D) 40A
Show Answer
Answer:
Correct Answer: B
Solution:
Magnetic field at the centre of circular loop $ B=\frac{{\mu_{0}}}{4\pi }\frac{2\pi i}{r}\Rightarrow 0.5\times {{10}^{-5}}=\frac{{{10}^{-7}}\times 2\times 3.14\times i}{5\times {{10}^{-2}}} $ i = 0.4 A
BETA
