Test Index

NCERT Class XII Chapter
Current Electricity
Questions With Solutions

© examsnet.com
Question : 3 of 24
Marks: +1, -0
(a) Three resistors 1 Ω, 2 Ω, and 3 Ω are combined in series. What is the total resistance of the combination?
(b) If the combination is connected to a battery of emf 12 V and negligible internal resistance, obtain the potential drop across each resistor.
Solution:  
(a) Total resistance of the combination in series, ReqR_{\text{eq}} = R1+R2+R3R_1+R_2+R_3
ReqR_{\text{eq}} = 1 Ω + 2 Ω + 3 Ω = 6 Ω
(b) Current in the circuit, I = 126\frac{12}{6} = 2 A
In series, same current flows through each resistor.
Now potential drop across 1 Ω,
V1V_1 = IR1IR_1 = 2 × 1 = 2 V
Potential drop across 2 Ω
V2V_2 = IR2IR_2 = 2 × 2 = 4 V , IR2IR_2 = 2 × 2 = 4 V
Potential drop across 3 Ω , V3V_3 = IR3IR_3 = 2 × 3 = 6 V
© examsnet.com
Go to Question:
Prev Question
Next Question