A) 11.5 V
B) 20 V
C) 21.5 V
D) 12,3 V
Correct Answer: A
Solution :
Here, emf of battery = 8V Internal resistance of the battery, \[r=0.5\,\Omega \] Voltage of D.C. supply = 120 V External resistance, \[R=15.5\,\Omega \]. When the battery of emf 8 V is charged from a DC supply of 120 V, the effective emf in the circuit is \[\varepsilon -120-8=112\,V\] Total resistance of the circuit \[=R+r\] \[=(15.5+0.5)\,\,\Omega =16\,\,\Omega \] \[\therefore \] Current in the circuit during charging \[I=\frac{\varepsilon }{R+r}=\frac{112}{16}=7A\] \[\therefore \] Terminal voltage of the battery, V = emf of the battery + voltage drop across the battery \[=8+Ir=8+7\,(0.5)=11.5\,V\]You need to login to perform this action.
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