Electrostatics Question 268
Question: To form a composite $ 16\mu F,\ 1000V $ capacitor from a supply of identical capacitors marked $ 8\mu F,\ 250V $ , we require a minimum number of capacitors [MP PET 1996; AIIMS 2000]
Options:
A) $ 0.34\ m $
B) $ 1.33\ m $
C) $ 13.4\ m $
D) $ 33.9\ m $
Show Answer
Answer:
Correct Answer: D
Solution:
If length of the foil is l then $ C=\frac{k{\varepsilon _{0}}(l\times b)}{d} $
therefore $ 2\times {{10}^{-6}}=\frac{2.5\times 8.85\times {{10}^{-12}}(l\times 400\times {{10}^{-3}})}{0.15\times {{10}^{-3}}} $
therefore l = 33.9 m
