question_answer

The magnitude of J in ampere is:

A)  0.1                                        

B)  0.3

C)  0.6                                        

D)  none of these

Correct Answer: A

Solution :

All the resistances are in parallel order, so voltage across them will be equal. \[\therefore \]  \[60\,I=(15+5)\,{{I}_{1}}\] \[\Rightarrow \]               \[60I=20\,{{I}_{1}}\]                        \[\Rightarrow \]               \[{{I}_{1}}=3\,\,I\]                                           ... (i) Again \[(15+5)\,{{I}_{1}}=10\,(1-I-{{I}_{1}})\] \[\Rightarrow \]               \[2{{I}_{1}}=1-I-{{I}_{1}}\] \[\Rightarrow \]               \[2\,(3l)=1-I-3I\] \[\Rightarrow \]               \[6I+4I=1\] \[\Rightarrow \]                               \[10I=1\] \[\therefore \]                  \[I=\frac{1}{10}=0.1\,A\]