Вправи: 40 (8)

Дано:

R₁= R₂ = R₃ = R₄ = R₀.

Розв’язання:

1) R = 4R₀;

2) $\frac{1}{R}$ = $\frac{1}{R_{0}}$ + $\frac{1}{R_{0}}$ + $\frac{1}{R_{0}}$ + $\frac{1}{R_{0}}$ = $\frac{4}{R_{0}}$ ; R = $\frac{R_{0}}{4}$;

3) R = R₀ + $\frac{R_{0}}{3}$ = $\frac{{4R}_{0}}{3}$;

4) R = R₀ + $\frac{R_{0}}{2}$ = $\frac{{5R}_{0}}{2}$;

5) R = $\frac{{2R}_{0}\ \bullet \ {2R}_{0}}{{2R}_{0} + \ {2R}_{0}}$ = R₀;

6) R = $\frac{R_{0}}{2}$ + $\frac{R_{0}}{2}$ = R₀;

7) $\frac{1}{R}$ = $\frac{1}{R_{0}}$ +$\frac{1}{{2R}_{0}}$ + $\frac{1}{R_{0}}$ = $\frac{5}{{2R}_{0}}$ ; R = $\frac{{2R}_{0}}{5}$;

8) R = $\frac{{3R}_{0}\ \bullet \ R_{0}}{{3R}_{0} + \ R_{0}}$ = $\frac{{3R}_{0}}{4}$;

9) R = R₀ + $\frac{{2R}_{0}\ \bullet \ R_{0}}{{2R}_{0} + \ R_{0}}$ = $\frac{{5R}_{0}}{3}$;

10)

R = $\frac{R_{0}\ \bullet \ \frac{{3R}_{0}}{2}}{\frac{{3R}_{0}}{2}}$ = $\frac{{3R}_{0}}{5}$.