Electronic problems

[selvaece2004]

1) The no of 2microF,400V capacitor needed to obtain 1.5microF,1600V is i)12 ii)8 iii)6 iv)4
2)In a Capacitor he electric charges is stored in dielectric how?
3)A sphere of radii 1m can attain a maximum potential of i)3*10^6V ii)30KV iii)1000V iv)3KV
4)Two coils having equal resistance but different inductance are connected in series.The time constant of the combination is i)sum of time constants of individual ii)average of '' '' iii)geometric mean of '' '' iv)product of '' '
5)12 identical wires of resistance 6 ohms each are arranged to form the edges of a cube.The effective resistance between the opposite corners of the cube is i)6ohms ii)5ohms iii)8ohms iv)4.5ohms(with explanation)
6)The voltage across R after t=0 and t=10seconds will be for 2Mohm and .5microF are connected across 100V supply with switch S. i)100V,63.2V ii)0V,63.2V iii)100V,36.8V iv)0v,36.8V

[JoeJester]

Can you post your thoughts on solving the problem?