The circuit consists of resistor $R$ and nonlinear element $X$ connected in series.

Current-voltage characteristics of resistor $R$ and element $X$ are depicted below.

When $0 \leq U \leq U_0$ CVCs of elements coincide. The circuit is powered using voltage $V$.

1 Determine the fraction $\eta_1$ of heat dissipated on element $X$ in cases $V \leq 2 U_0$ and $V=4 U_0$.

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2 Sketch CVC of two elements $X$ connected in series.

Let's connect one element $X$ in series to the circuit considered above. Determine the fraction $\eta_2$ of heat dissipated on two elements $X$ when $V=4U_0$.

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3 Sketch CVC of two elements $X$ connected in parallel.

Let's reconnect extra element $X$ so that it is in parallel with the initial $X$. Determine the fraction $\eta_3$ of heat dissipated on two elements $X$ when $V=4U_0$.

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