Tính $f_1, f_2, \cos \phi_1$
- Thread starter chinhanh9
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Em có thể tham khảo một lời giải tại:
http://hieubuidinh.blogspot.com/2014/05/tinh-f1f2cosvarphi-1cosvarphi-2.html
Muộn
Active Member
Công thức: $\cos \varphi _{1}=\cos \varphi _{2}=\sqrt{\dfrac{2f_{C}}{f_{C}+f_{L}}}$
$\rightarrow \cos \varphi _{1}=\cos \varphi _{2}=\sqrt{\dfrac{2f_{1}}{2f_{1}+100}}$
$\rightarrow \dfrac{\left(U\cos \varphi _{1}\right)^{2}}{R}=0,75\dfrac{U^{2}}{R}$
$\rightarrow \dfrac{2f_{1}}{2f_{1}+100}=0,75\rightarrow f_{1}=150,f_{2}=250$
$\rightarrow \cos \varphi _{1}=\cos \varphi _{2}=\dfrac{\sqrt{3}}{2}$
$\rightarrow \cos \varphi _{1}=\cos \varphi _{2}=\sqrt{\dfrac{2f_{1}}{2f_{1}+100}}$
$\rightarrow \dfrac{\left(U\cos \varphi _{1}\right)^{2}}{R}=0,75\dfrac{U^{2}}{R}$
$\rightarrow \dfrac{2f_{1}}{2f_{1}+100}=0,75\rightarrow f_{1}=150,f_{2}=250$
$\rightarrow \cos \varphi _{1}=\cos \varphi _{2}=\dfrac{\sqrt{3}}{2}$