(1) 10
70.
Solve for the RC time constant.
(2) 63
R = 69,000 ohms
(3) 90
(4) 100
C =.001 f
t=
69 sec
71.
What is the formula used to compute the RC time constant of any RC circuit?
FORMULA:
t = RC
72.
At this point, we must stress a very important point:
When C is charging, the voltage on C (EC) plus the voltage across R (ER) must
equal Eapp.
100 volts DC are applied to the RC circuit in fig. 8.
Figure 8.
At the instant the switch is closed, C starts changing.
In .1 RC time, EC = 10 volts and ER = 90 volts (EC +ER = Eapp).
In 1 RC time, EC = 63 volts and ER = 37 volts (EC + ER = Eapp).
In 2.3 RC time, EC = 90 volts and ER = 10 volts (EC + ER = Eapp).
In 10 RC time, EC = 100 volts and ER = 0 volts (EC + ER= Eapp).
With 150 volts applied to an RC circuit for .1 RC time, EC = 15 volts
and ER =
volts.
1-23
IT0351
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