21.51. Set Up:
The stored energy is
The rate at which thermal energy is dissipated is
Solve: (a)
(b)
(c)
No. If
I
is constant then the stored energy
U
is constant. The energy being consumed by the resistance of the induc
tor comes from the emf source that maintains the current; it does not come from the energy stored in the inductor.
21.52. Set Up:
The time constant is
The current as a function of time is
The energy
stored in the inductor is
Solve: (a)
(b)
The maximum current is when
and is equal to
(c)
(d)
21.53. Set Up:
The loop rule applied to the circuit gives
the voltage across the
inductor. The current as a function of time is given by
At
at
Solve: (a)
At
and
(b)
At
and
Initially,
the voltage across
the resistor is zero, and the full battery emf appears across the inductor.
(c)
The time constant is
When
(d)
When
Reflect:
Initially
and the full battery voltage is across the inductor. After a long time, the full battery voltage is
across the resistor.
21.54. Set Up:
This is the end of the preview.
Sign up
to
access the rest of the document.
 Spring '07
 Shoberg
 Energy, Thermal Energy, long time, Inductor, 2 2 5 0.540 J, 2 2 5 3.52 3 1025 J

Click to edit the document details