A nullator is defined as a circuit element where the voltage across the device and the current through the device are both zero. A series combination of a nullator and a resistor of value, $R$, will behave as a

The number of junctions in the circuit is

In the given circuit, for voltage V_y to be zero, the value of β should be ______. (Round off to 2 decimal places).

Two single-core power cables have total conductor resistances of $0.7 \Omega$ and $0.5 \Omega$ respectively and their insulation resistances (between core and sheath) are $600 \mathrm{M} \Omega$ and $900 \mathrm{M} \Omega$ respectively. When the two cables are joined in series, the ratio of insulation resistance to conductor resistance is $\_\_\_\_$ $\times 10^6$