Magnetic Effects Of Current Question 119
Question: A long wire carries a steady current. It is bent into a circle of one turn and the magnetic field at the centre of the coil is B. It is then bent into a circular loop of n turns. The magnetic field at the centre of the coil will be [AIEEE 2004]
Options:
A) nB
B) n2B
C) 2nB
D) 2n2B
Show Answer
Answer:
Correct Answer: B
Solution:
Magnetic field at the center of single turn loop $ B=\frac{{\mu_{0}}}{4\pi }.\frac{2\pi i}{r} $ , magnetic field at the center of n-turn loop $ B_{n}=( \frac{{\mu_{0}}}{4\pi }.\frac{2\pi i}{r/n} )\times n\Rightarrow B_{n}=n^{2}B $
BETA
