The diagram shows an RL circuit with a switch. E=110V, R1=10 ohm, R2=43 ohm, R3=
ID: 1304090 • Letter: T
Question
The diagram shows an RL circuit with a switch. E=110V, R1=10 ohm, R2=43 ohm, R3=58 ohm, and L=5H.
*All answers in A
1. The switch has been closed and after waiting a long time it is opened. What is I1 just after this opening?
2. What is I1 a very long time after the switch is closed?
3. What is I1 just after the switch is closed?
4. The switch has been closed and after waiting a long time it is opened. What is I1 a very long time after the switch is opened?
5. The switch has been closed and after waiting a long time it is opened. What is I1 just after this opening?
6. What is I2 a very long time after the switch is closed?
7. The switch has been closed and after waiting a long time it is oepend. What is I1 a very long time after the switch is opened?
8. What is I2 just after the switch is closed?
Explanation / Answer
The diagram shows an RL circuit with a switch. E=110V, R1=10 ohm, R2=43 ohm, R3=58 ohm, and L=5H.
*All answers in A
1. The switch has been closed and after waiting a long time it is opened. What is I1 just after this opening?
steady state achieved for inductor and switch opened.. inductor , resistors form a series circuit after switch is opened and inductor does not allow sudden changes in current so
steady state current = E/R2 = 110/43 = 2.558 amps
current I1 = -2.558 amps (series circuit and opposite direction to I2)
2. What is I1 a very long time after the switch is closed?
steady state achieved for inductor so
current I1 = E/R1 = 110/10 = 11 A
3. What is I1 just after the switch is closed?
just after switch is closed
inductor is open circuited and I1 = E/R1 = 110/10 = 11 A
4. The switch has been closed and after waiting a long time it is opened. What is I1 a very long time after the switch is opened?
I1 a very long time after the switch is opened = zero (inductor fully discharged)
5. The switch has been closed and after waiting a long time it is opened. What is I2 just after this opening?
I2 = 2.558 amp as calculated in 1st problem
6. What is I2 a very long time after the switch is closed?
steady state current = E/R2 = 110/43 = 2.558
7. The switch has been closed and after waiting a long time it is oepend. What is I2 a very long time after the switch is opened?
I2 after complete discharge very long time after the switch is opened = zero
8. What is I2 just after the switch is closed?
I2 = zero (sudden change in current not allowed in inductor so current is zero.. inductor acts as open circuit just after switch is closed)