COMEDK2017PhysicsCurrent Electricity
If the potential difference across the internal resistance r₁ is equal to the emf E of the battery, then
Options
- AR=r₁+r₂
- BR= r₁ r₂
- CR=r₁-r₂
- DR= r₂ r₁^ *
Correct answer
C. R=r₁-r₂
Step-by-step solution
Total emf of circuit, E_ T =E+E=2 E Total resistance of circuit, R_ T =r₁+r₂+R Current flowing through the circuit, i= E_ T R_ T = 2 E r₁+r₂+R ...(i) As per question E=i r₁ i= E r₁ ...(ii) From Eqs. (i) and (ii), we get array ll & E r₁ = 2 E r₁+r₂+R & r₁+r₂+R=2 r₁ & R=r₁-r₂ array