Explanation:
10
/9 Ω
potential difference across the cell in open circuit is the emf of the cell.
Hence, emf E=2.2V
when, circuit is closed, potential difference across cell is given by V=E−Ir
And,
I= E/
R+r
Hence, V= E− Er/
R+r
⟹ V= ER/
R+r
⟹ 1.8= 2.2×5
/5+r
⟹9+1.8r=11
⟹ r= 2/ 1.8 Ω
⟹ r= 10/9 Ω
Physics involves math because calculations have to be made and u use math to make calculations
Friction produces heat hope this helps
