An LR circuit has a resistance R = 25 $\Omega$,an inductance L = 5.4 mH,and a battery of EMF = 9.0 V.How much energy is stored in the inductance of this circuit when a steady current is achieved?
A)zero
B)0.35 J
C)0.35 mJ
D)0.70 mJ
E)0.97 mJ

Question

Quizplus · Accepted Answer

The energy stored in the inductance of an LR circuit is given by:

U = (1/2) * L * I^2

where U is the energy, L is the inductance, and I is the current.

We are given that the resistance R = 25 Ω and the battery EMF = 9.0 V. The steady state current in the circuit can be found using Ohm's Law:

I = EMF / R = 9.0 V / 25 Ω = 0.36 A

Therefore, the energy stored in the inductance is:

U = (1/2) * L * I^2 = (1/2) * 5.4 mH * (0.36 A)^2 = 0.35 mJ

So the best choice is C.

An LR Circuit Has a Resistance R = 25 Ω\OmegaΩ ,An Inductance L = 5

An LR Circuit Has a Resistance R = 25 $\Omega$ ,An Inductance L = 5