Question

Answer 1

Câu 4.

\(R_{tđ}=\dfrac{U}{I}=\dfrac{9}{1,5}=6\Omega\)

Theo bài ta có: \(R_1+R_2=6\) và \(R_1=2R_2\)

\(\Rightarrow\left\{{}\begin{matrix}R_1=4\Omega\\R_2=2\Omega\end{matrix}\right.\)

Bài 5.

Tiết diện dây:

\(R=\rho\dfrac{l}{S}\Rightarrow S=\dfrac{\rho\cdot l}{R}=\dfrac{2,8\cdot10^{-8}\cdot100}{5}=5,6\cdot10^{-7}\left(m^2\right)=0,56mm^2\)

 

 

Answer 2

Bài 5:

\(R=p\dfrac{l}{S}\Rightarrow S=\dfrac{p\cdot l}{R}=\dfrac{2,8\cdot10^{-8}\cdot100}{5}=5,6\cdot10^{-7}m^2\)