Loading....
Coupon Accepted Successfully!

 

Grouping of Cells

A group of cell is called a battery. In series grouping of cells their emfs are additive or subtractive while their internal resistances are always additive. If dissimilar plates of cells are connected together their emfs are added to each other while if their similar plates are connected together their emfs are subtractive (Fig. 20).
 
72366.png
Fig. 20

Series grouping

In series grouping, anode of one cell is connected to the cathode of other cell and so on. If n identical cells are connected in series,
 
72377.png
Fig. 21
  • Equivalent emf of the combination, Eeq = nE
  • Equivalent internal resistance, req = nr
  • Main current = Current from each cell 70772.png
  • Potential difference across external resistance V = iR
  • Potential difference across each cell V’ = V/n
  • Power dissipated in the external circuit70784.png
  • Condition for maximum power R = nr and 70790.png
  • This type of combination is used when nr << R.

Parallel grouping

In parallel grouping, all anodes are connected at one point and all cathode are connected together at other point (Fig. 22). If n identical cells are connected in parallel,
 
72385.png
Fig. 22
  • Equivalent emf, Eeq = E
  • Equivalent internal resistance, Req = r/n
  • Main current, 70796.png
  • Potential difference across external resistance = p.d. across each cell, V = iR
  • Current from each cell, 70805.png
  • Power dissipated in the circuit, 70811.png
  • Condition for maximum power is R = r/n and 70817.png
  • This type of combination is used when nr >> R

Mixed grouping

If n identical cells are connected in a row and such m rows are connected in parallel as shown in Fig. 23, then
 
72402.png
Fig. 23
  • Equivalent emf of the combination, Eeq = nE
  • Equivalent internal resistance of the combination, 70827.png
  • Main current flowing through the load, 70836.png
  • Potential difference across load, V = iR
  • Potential difference across each cell, 70842.png
  • Current from each cell, 70851.png
  • Condition for maximum power, 70857.png and70863.png
  • Total number of cell = mn




Test Your Skills Now!
Take a Quiz now
Reviewer Name