In the circuit shown in the figure below, ε1 = 28.0 V, R1 = 7.00 Ω, and R2 = 2.00 Ω.
(a) Find the current in resistor R.
(b) Find the resistance R.
(c) Find the unknown emf ε.
(d) If the circuit is broken at point x, what is the current in resistor R?