Six identical resistors connected between points A, B and C as shown in diagram. The equivalent resistance would be maximum between.

2 points A and B are at electric potentials $10 \mathrm{V}$ and $100 \mathrm{V}$ respectively. A charge $q$ is taken from A to B and $18 \mathrm{Joule}$ of work is done. The value of $q$ is

The resistance of rheostat shown in the figure is $0-30 \mathrm{\Omega }$, Neglecting the resistance of ammeter and connecting wire the minimum and maximum currents through the ammeter will be