Four resistors are connected to form a quadrilateral ABCD such that the resistance of arm AB is 10 , arm BC is 20 , arm CD is 60 , and arm AD is 30 . A 50 resistor is connected between the junctions B and D. A battery of EMF 12 V and internal resistance 1.5 is connected across the junctions A and C. What is the current drawn from the battery?

Step-by-step solution

The given circuit is a Wheatstone bridge with the battery connected across junctions A and C. The resistances of the arms are R_ AB = 10 , , R_ BC = 20 , , R_ AD = 30 , , and R_ CD = 60 , . Checking the balance condition of the Wheatstone bridge: R_ AB R_ BC = 10 20 = 1 2 R_ AD R_ CD = 30 60 = 1 2 Since R_ AB R_ BC = R_ AD R_ CD , the bridge is balanced. Therefore, no current flows through the 50 , resistor connected between junctions B and D. The equivalent resistance of the upper branch ABC is R_ ABC = 10 + 20 =