For a cell, terminal potential difference is 2.2 ~V when circuit is open. If it reduces to 1.8 ~V when the cell is connected to a resistance of 5 . The internal resistance of cell (r) is then:

Step-by-step solution

Terminal potential difference aligned & V=E-I r & V=E- [ E R-r ] r= E R R+r aligned From given condition =E=2.2 and where R=5 then potential V=1.8 ~V Therefore 1.8= 2.2 5 5+r r= 10 9