Magnetic Effects Of Current Question 418
Question: The magnetic field due to a current carrying circular loop of radius 3 cm at a point on the axis at a distance of 4 cm from the centre is $ 54,\mu T $ . What will be its value at the centre of loop?
Options:
A) $ 125\mu T $
B) $ 150\mu T $
C) $ 250\mu T $
D) $ 75\mu T $
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Answer:
Correct Answer: C
Solution:
[c] $ B=\frac{{\mu_{0}}ia^{2}}{1{{(x^{2}+a^{2})}^{3/2}}} $ $ B’=\frac{{\mu_{0}}i}{2a}=\frac{{\mu_{0}}i,a^{2}}{2a{{(x^{2}+a^{2})}^{3/2}}}( \frac{{{(x^{2}+a^{2})}^{3/2}}}{a^{2}} ) $ $ B’=\frac{B.{{(x^{2}+a^{2})}^{3/2}}}{a^{3}} $ Put $ x=4\And a=3\Rightarrow B’=\frac{54(5^{3})}{3\times 3\times 3}=250\mu T $
BETA
