Rl Time Constant
Mediumphysics
Time constant τ for RL circuit (R, L) equals?
Select the correct option:
Solution
Incorrect! Answer:
L/R
- Definition: The time constant (τ) of an RL circuit determines how quickly the current reaches its steady-state value after a switch is closed or opened.
- Current Growth Equation: I(t)=Imax(1−e−t/τ).
- Derivation: From Kirchhoff's Loop Law: ϵ−Ldtdi−iR=0. Solving this differential equation reveals τ=L/R.
- Physical Meaning: After one time constant (t=τ), the current grows to about 63.2% of its maximum value (Imax=E/R).
- Inversely: For decay, I(t)=I0e−t/τ, current drops to 36.8% after t=τ.
🔒 Solution Hidden from View
Submit your answer to unlock the detailed step-by-step solution.
About This Question
- Subject
- physics
- Chapter
- em induction and ac
- Topic
- rl time constant
- Difficulty
- Medium
- Year
- 2025
Solution
Correct Answer:
L/R
- Definition: The time constant (τ) of an RL circuit determines how quickly the current reaches its steady-state value after a switch is closed or opened.
- Current Growth Equation: I(t)=Imax(1−e−t/τ).
- Derivation: From Kirchhoff's Loop Law: ϵ−Ldtdi−iR=0. Solving this differential equation reveals τ=L/R.
- Physical Meaning: After one time constant (t=τ), the current grows to about 63.2% of its maximum value (Imax=E/R).
- Inversely: For decay, I(t)=I0e−t/τ, current drops to 36.8% after t=τ.
This medium difficulty physics question is from the chapter em induction and ac, covering the topic of rl time constant. It appeared in the 2025 exam.
Looking for more practice? Explore all physics questions or browse em induction and ac questions on RankGuru.