A potential difference of $4 \mathrm{V}$ is applied to two resistors of $6 \mathrm{\Omega }$ and $2 \mathrm{\Omega }$ connected in series. Calculate:

(a) the combined resistance

(b) the current flowing

(c) the potential difference across the $6 \mathrm{\Omega }$ resistor

A potential difference of $6 \mathrm{V}$ is applied to two resistors of $3 \mathrm{\Omega }$ and $6 \mathrm{\Omega }$ connected in parallel. Calculate:

(a) the combined resistance

(b) the current flowing in the main circuit

(c) the current flowing in the $3 \mathrm{\Omega }$ resistor.

Two resistances are connected in series as shown in the diagram:

(i) What is the current through the $5 \mathrm{ohm}$ resistance?
(ii) What is the current through $R?$
(iii) What is the value of $R?$
(iv) What is the value of $V?$