NTA Abhyas JEE Main2020PhysicsElectrostaticsPractice
Two capacitors C 1 and C 2 in a circuit are joined as shown in the figure. The potentials of points A and B are V 1 and V 2 respectively. Then the potential of point D will be
Options
- AV 1 + V 2 2
- BC 2 V 1 + C 1 V 2 C 1 + C 2
- CC 1 V 1 + C 2 V 2 C 1 + C 2
- DC 2 V 1 - C 1 V 2 C 1 + C 2
Correct answer
C. C 1 V 1 + C 2 V 2 C 1 + C 2
Step-by-step solution
Consider the potential at D be V . The potential drop across C 1 is ( V − V 1 ) and C 2 is ( V 2 − V ) ∴ q 1 = C 1 ( V − V 1 ) ,   q 2 = C 2 ( V 2 − V ) As q 1 = q 2 [capacitors are in series] ∴ C 1 ( V − V 1 ) = C 2 ( V 2 − V ) V = C 1 V 1 + C 2 V 2 C 1 + C 2