14.4 RL Circuits

Resistor and inductor in series across a switch: exponential growth and decay of current, the L/R time constant, and the voltage across each element.

University Physics Volume 2, 14.4 RL Circuits

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5 exercises

14.4 Exercise 2

(a) If the current in the circuit of in the figure(b) increases to $90 \%$ of its final value after 5.0 s, what is the inductive time constant? (b) If $R = 20 \Omega$ , what is the value of the self-inductance? (c) If the $20 - \Omega$ resistor is replaced with a $100 - \Omega$ resister, what is the time taken for the current to reach $90 \%$ of its final value?

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14.4 Exercise 4

Use Lenz’s law to explain why the initial current in the RL circuit of the figure(b) is zero.

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14.4 Exercise 6

Does the time required for the current in an RL circuit to reach any fraction of its steady-state value depend on the emf of the battery?

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14.4 Exercise 8

At what time is the voltage across the inductor of the RL circuit of the figure(b) a maximum?

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14.4 Exercise 10

If the emf of the battery of the figure(b) is reduced by a factor of 2, by how much does the steady-state energy stored in the magnetic field of the inductor change?

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