- proof??Showthatthefractionalhalf
- Show that the fractnal half-width of a resonance curve for an RLC circuit
is given by △ωd/ωο = R*(3C/L)^0.5
in which ωο is the angular frequency
at resonance and △ωd is the width of the resonance curve at half-amplitude
- 俺不是万能的,啥问题都能回答,老实说,“ half-width ”(是半宽度吧?)俺连听都没听说过,汗!好在RL电路的谐振还是学过的,于是俺连猜带蒙,把这道题解出来:
对于RLC电路的谐振有式子
I/Io=1/[1+Q²(ω/ωo-ωo/ω)²]^(½),
其中,Q=(1/R)(L/C)^(½)为品质因数,
所谓“the fractional half-width of a resonance curve for an RLC circuit ”,俺估计,这个“the fractional half-width ”就是指I/Io=1/2,于是有
1/2=1/[1+Q²(ω/ωo-ωo/ω)²]^(½),
可以求得I/Io=1/2时的ω的值,由这个式子得到,
ω/ωo-ωo/ω=±R(3C/L)^(½),
显然,ω有两个值ω1和ω2,设ω2>ω1,解之得
ω2=[R(3C/L)^(½)±ωo(3R²C/L+4)^(½)]/2,
ω1=[-R(3C/L)^(½)±ωo(3R²C/L+4)^(½)]/2,
由“△ωd is the width of the resonance curve at half-amplitude”俺认为
△ωd=ω2-ω1=ωoR(3C/L)^(½),
于是,
△ωd/ωο=R(3C/L)^(½),
终于凑对结果了,也不知道是对是错,管他呢,反正,俺也是猜的,提交回答吧!