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A short bar magnet oscillates in VMM with a frequency of 10Hz. If a downward current of 15A is established in a long thin vertical wire placed 20 cm west of the magnet, its frequency was found to be 5Hz. If a TG containing 500 turns with radius of each turn 4pi cm is used at that place & a current of 10mA is allowed to pass through it. Find the deflection of magnetic needle in the TG |
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Answer» Solution :`n=1/(2PI)SQRT((MB_("net"))/I),npropsqrt(B_("net"))rArr(n_(1))/n=sqrt((B_(H)~B)/(B_(H)))` Where `B=(mu_(0))/(2pi)I/r=2xx10^(-7)xx15/20xx10^(2)=15muT` `(5/10)^(2)=((B_(H)hatB)/(B_(H)))` a) if `B_(H)gtBrArr4B_(H)~4B=B_(H)rArr3B_(H)=4B` `B_(H)=4/3B=4/3xx15muT=20muT` In case of T.G. `(mu_(0)ni)/(2rB_(H))=tantheta` `(4pixx10^(-7)xx500xx10^(-2))/(2(4pi)10^(-2)xx20xx10^(-6))=tantheta` `tantheta=25/20`, `theta=tan^(-1)(5/4)` b) if `BgtB_(H)rArr4B-4B_(H)=B_(H)rArr5B_(H)=4B` `rArrB_(H)=4/5xx15muT=12muT=theta-tan^(-1)(25/12)` |
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