200 alkaline accumulators are to be charged by a dynamo generating a voltage of 230 V. The e.m.f. of each
accumulator is 1.4 V, the internal resistance 0.01 ohm, the charging current 30 A. Suggest the circuit diagram and calculate the resistance of the rheoslat.

Answer

1 oh.

Explanation

The accumulators should best be connected in series in two groups of 100 cells each, both groups being connected in parallel and the entire battery connected through a rheostat to the terminalsof, a dynamo (Fig. 26.11). The e.m.f. of the battery is `delta=ne//2 = 100 xx 1.4 =140V` the internal resistance is `R_(l)=nr//4 `= 0.5 ohm. The current in the circuit is I=2i= 60 A. Ohm.s law can be written in the following form: `trianglePsi=delta=I=(R+R_(i))`, from which `R=(triangle Psi-epsi)/(I)-R_(i)`.