RL Discharge Time Constant

In summary, the conversation revolved around a series RL circuit consisting of a 10V supply, a switch, R1 (200Ω), R2 (100Ω), and a 1H inductance. The time constants for when the switch is open and closed were discussed, with the formula t = L/R being used to calculate them. The time constants were found to be 0.002s when the switch is closed and 0.003s when it is open.
  • #1
Kev1n
40
0
1. circuit consists of 10v supply, a switch, R1 (200ohm), R2 (100ohm) in series with a 1H inductance. with R3 (200ohm) across R1 and Inductance. I have to work out the time constants when switch is open and when closed.



2. when closed I have used 1 time constant = t = L/R, then 5 x L/R. I struggle now with the open formula



3. t= 1/200 = 0.005s anf 5 x L/R = 0.025s - using 200 ohm as rt for R2 & R3 as equivalent of series. Now struggling with open switch is it just the same with Rt being 266.67 ohms
 
Physics news on Phys.org
  • #2
?

Hi there!

Based on the information provided, it seems like you are working with a series RL circuit. In this type of circuit, the time constant can be calculated using the formula t = L/R, where L is the inductance in henries and R is the total resistance in the circuit.

When the switch is closed, the total resistance in the circuit is given by R1 + R2 + R3. So the time constant in this case would be t = 1H / (200Ω + 100Ω + 200Ω) = 0.002s.

When the switch is open, the total resistance in the circuit is given by R1 + R2. So the time constant in this case would be t = 1H / (200Ω + 100Ω) = 0.003s.

I hope this helps! Let me know if you have any further questions.
 

1. What is the RL discharge time constant?

The RL discharge time constant is a measure of how quickly the voltage across a resistor (R) and inductor (L) circuit decreases when the circuit is opened or switched off. It is represented by the symbol τ (tau) and is calculated by multiplying the resistance (R) by the inductance (L).

2. How is the RL discharge time constant calculated?

The RL discharge time constant (τ) is calculated by multiplying the resistance (R) by the inductance (L). The formula for calculating τ is: τ = R x L.

3. What is the significance of the RL discharge time constant?

The RL discharge time constant is an important parameter in understanding the behavior of RL circuits. It determines the rate at which the voltage across the circuit decreases when the circuit is switched off or opened. It also affects the time it takes for the current in the circuit to reach zero and the energy dissipated in the circuit.

4. How does the RL discharge time constant affect the behavior of RL circuits?

The RL discharge time constant affects the behavior of RL circuits by determining the rate at which the voltage across the circuit decreases when the circuit is switched off or opened. A higher time constant means the voltage will decrease more gradually, while a lower time constant means the voltage will decrease more quickly. This also impacts the time it takes for the current in the circuit to reach zero and the energy dissipated in the circuit.

5. How can the RL discharge time constant be measured or determined experimentally?

The RL discharge time constant can be determined experimentally by measuring the voltage across the circuit as it discharges and plotting it on a graph. The slope of the graph will give the time constant, as it represents the rate of change of voltage with respect to time. Alternatively, it can be calculated using the formula τ = R x L, if the values of resistance and inductance are known.

Similar threads

  • Introductory Physics Homework Help
Replies
3
Views
2K
Replies
4
Views
1K
  • Introductory Physics Homework Help
Replies
4
Views
990
  • Introductory Physics Homework Help
Replies
5
Views
6K
  • Introductory Physics Homework Help
Replies
9
Views
6K
  • Introductory Physics Homework Help
Replies
1
Views
1K
  • Introductory Physics Homework Help
Replies
9
Views
6K
  • Introductory Physics Homework Help
Replies
4
Views
4K
  • Introductory Physics Homework Help
Replies
11
Views
1K
  • Introductory Physics Homework Help
Replies
9
Views
9K
Back
Top