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Question
What is the energy required to build up current of 1A in an inductor of 20 mH?
Options
10 mJ
20 mJ
20 J
10 J
Solution
10 mJ
Explanation:
Step 1:
Let E = energy required
Substitute the given values from Question,
Let, inductance = L
Current = I
`L = 20 mH` ....(1)
`I = 1A` .....(2)
Applying the concept of Energy stored in the coil.
We get, `E = 1/2 LI^2` .....(3)
Step 2:
Substitute from (1), (2), and (3) and calculate:
`E = 1/2 LI^2`
`E = 1/2 xx 20 xx 10^-3 xx 1`
E = 10 mJ
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