Question
Download Solution PDFA coil of inductance 2 H having negligible resistance is connected to a source of supply whose voltage is given by V = 3t volt. (where t is in second). If the voltage is applied when t = 0, then the energy stored in the coil after 4 s is ____ J.
Answer (Detailed Solution Below) 144
Detailed Solution
Download Solution PDFExplanation:
Relation among voltage(V), current(i) and inductance(L) is given as:
V = L
Energy stored in the coil is given as:
E =
where I = current in the coil after time t s.
From equation (1) we have,
Ldi = Vdt ⇒
Given,
L = 2 H, V = 3t, t = 4 s.
∴
Putting the given values in equation (3) we get-
I = 12 A.
Now using equation (2) we get,
E =
Hence E = 144 J is the correct answer.
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