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 $\_\_\_\_$ $\times 10^6$

In the given circuit, the value of capacitor $C$ that makes current $I=0$ is $\_\_\_\_$ $\mu \mathrm{F}$.

A three-phase balanced voltage is applied to the load shown. The phase sequence is RYB. The ratio $\left|\frac{I_B}{I_R}\right|$ is $\_\_\_\_$ .

A signal generator having a source resistance of $50 \Omega$ is set to generate a 1 kHz sinewave. Open circuit terminal voltage is 10 V peak-to-peak. Connecting a capacitor across the terminals reduces the voltage to 8 V peak-to-peak. The value of this capacitor is $\_\_\_\_$ $\mu \mathrm{F}$. (Round off to 2 decimal places)