Electro Magnetic Induction And Alternating Currents Question 576
Question: The equivalent inductance of two inductances is 2.4 henry when connected in parallel and 10 henry when connected in series. The difference between the two inductances is [MP PMT 2000]
Options:
A) 2 henry
B) 3 henry
C) 4 henry
D) 5 henry
Show Answer
Answer:
Correct Answer: A
Solution:
$ L_{S}=L_{1}+L_{2}=10H $ ….. (i) $ L_{P}=\frac{L_{1}L_{2}}{L_{1}+L_{2}}=2.4H $ ….. (ii) On solving (i) and (ii) L1L2 = 24 ….. (iii) Also $ {{(L_{1}-L_{2})}^{2}}={{(L_{1}+L_{2})}^{2}}-4L_{1}L_{2} $
$ \Rightarrow {{(L_{1}-L_{2})}^{2}}={{(10)}^{2}}-4\times 24=4 $
$ \Rightarrow L_{1}-L_{2}=2H $
