question_answer 3)

(a) Three resistors 1, 2 and 3 are combined in series. What is the total resistance of the combination?                 (b) If the combination is connected to a battery of e.m.f. 12 V and negligible internal resistance, obtain the potential drop across each resistor.  

Answer:

(a) Using Req = R1+ R2 + R3, we get                 Req = 1 + 2 + 3 = 6                 (b) Using V = IR, we get                                 Then, Voltage drop across R1 is given by,                 V1 = IR1 = 2 × 1 = 2V                 Voltage drop across R2 is given by,                 V2 = IR2 = 2 x 2 = 4V                 Voltage drop across R3 is given by,                 V3 = IR3 = 2 x 3 = 6 V.