Electrostatics Question 554
Question: Four capacitors are shown with their respective capacities and the P.D. applied. The charge and the P.D. across the $ 4\mu F $ capacitor will be
Options:
A) $ 600\mu C;\ 150\ volts $
B) $ 300\mu C;\ 75\ volts $
C) $ 800\mu C;\ 200\ volts $
D) $ 580\mu C;\ 145\ volts $
Show Answer
Answer:
Correct Answer: D
Solution:
Total capacitance $ \frac{1}{C}=\frac{1}{20}+\frac{1}{8}+\frac{1}{12} $ t
herefore $ C=\frac{120}{31}\mu F $ Total charge $ Q=CV=\frac{120}{31}\times 300=1161\mu C $
Charge, through 4 mF condenser $ =\frac{1161}{2}=580\mu C $
and potential difference across it $ =\frac{580}{4}=145V $
