Problem: From lowest to highest, rank the current in the main branch of the circuit – that is – rank the current passing through point j. a. A, B, C b. A, C, B c. B, A, C d. B, C, A e. C, A, B f. C, B, A

Ohm's law:

$\boxed{\mathit{i}\mathbf{=}\frac{\mathbf{V}}{\mathbf{R}}}$

The bulbs act as resistors.

Assuming that each bulb has a resistance of R, we can get the equivalent resistance for the different cases from where we can get current. 

Remember,

Equivalent resistance for resistors in parallel:

$\boxed{\frac{\mathbf{1}}{{\mathbf{R}}_{\mathbf{eq}}}\mathbf{=}\frac{\mathbf{1}}{{\mathbf{R}}_{\mathbf{1}}}\mathbf{+}\frac{\mathbf{1}}{{\mathbf{R}}_{\mathbf{2}}}\mathbf{+}\mathbf{.}\mathbf{.}\mathbf{.}\mathbf{+}\frac{\mathbf{1}}{{\mathbf{R}}_{\mathbf{n}}}}$

Equivalent resistance for resistors in series:

$\boxed{{\mathbf{R}}_{\mathbf{eq}}\mathbf{=}{\mathbf{R}}_{\mathbf{1}}\mathbf{+}{\mathbf{R}}_{\mathbf{2}}\mathbf{+}\mathbf{.}\mathbf{.}\mathbf{.}\mathbf{+}{\mathbf{R}}_{\mathbf{n}}}$