question_answer

The current 1 drawn from the 5 V source will be

A) 0.33 A                                   

B) 0.5 A

C) 0.67 A                                   

D) 0.17 A

Correct Answer: B

Solution :

The given circuit can be redrawn as which is a balanced Wheatstone?s bridge and hence no current flows in the middle resistor, so equivalent circuit would be as shown  below. \[10\Omega \]and \[20\Omega \]resistances are in series \[\therefore \]  \[R'=10\Omega +20\Omega =30\Omega \] Similarly, \[5\Omega \]and \[10\Omega \]are in series     \[R''=15\Omega \] Now, R? and R? are in parallel \[\therefore \]   \[R=\frac{15\times 30}{15+30}=10\Omega \] So,     \[I=\frac{V}{R}=\frac{5}{10}=0.5A\]