The equivalent resistance across A and B is
Three resistors having resistances 2 Ω, 3 Ω and 4 Ω are connected so that the equivalent resistance is 9 Ω. The resistors are connected in:
Circuit diagram shows that resistors 2Ω, 4Ω and RΩ connected to a battery of e.m.f. 2 V and internal resistance 3Ω. A main current of 0.25 A flows through the circuit. What is the p.d. across the 4Ω resistor?