Question

Four cells, each of e.m.f 2V and internal resistance 0.2Ω each are connected in series to form a battery. This battery is connected to an ammeter, a resistance 1.2 and then to a set of resistance of 4Ω, 6Ω and 12Ω in parallel to complete the overall circuit in series. 

(a) Draw circuit diagram of arangment. 

(b) Calculate total internal resistance 

(c) Total e.m.f. 

(d) Current recorded by ammeter. 

(e) Current flowing through 6 wire in parallel.

(f) Drop in potential across the terminals of the battery. 

Answer 1

(a) Circuit diagram :

(b) Total internal resistance r = 4 × 0.2 = 0.8Ω

(c) Total e.m.f. = 4 × 2 = 8v 

(d) Current recorded by ammeter? 

R₁ across CD 1/R₁ = 1/4 + 1/6 + 1/12 = R₁ = 2Ω 

Total resistance (0.8 + 1.2 + 2) = 4Ω I = v/R = 8/4 = 2A

(e) Vacross CD = IR₁= 2 × 2 = 4V 

Current through 6Ω = v/R = 4/6 = 0.67A 

(f) droop in potential across the terminals of the battery E – V = Ir = 2 × 0.8 = 1.6V