Q57P In the circuit shown in Fig. P30... [FREE SOLUTION]

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University Physics with Modern Physics

Hugh D. Young, Roger A. Freedman

Physics

14th edition Edition 路 1596 pages

ISBN: 9780321973610

Chapter 4: Q57P (page 1016)

In the circuit shown in Fig. P30.57, the switch S has been open for a long time and is suddenly closed. Neither the battery nor the inductors have any appreciable resistance. What do the ammeter and the voltmeter read (a) just after S is closed; (b) after S has been closed a very long time; (c) 0.115 ms after S is closed?

Short Answer

Expert verified

A) Current is $i= \frac{emf}{R}$ for RC circuit and $i = 0$ for RL circuit b) Current is zero for RC circuit and $i_{R} = \frac{emf}{R}$ for RL circuit.

Step by step solution

Concept when S is closed

Just after the switch is closed in the R 鈥� C circuit, the current flow through the resistor R and the initial current is $i = \frac{emf}{R}$ While just after the switch is closed in the R 鈥� L circuit, the current wouldn't flow through the circuit and the initial current is zero. $i = 0$

Concept when after S has been closed a very long time

After a long time, for R 鈥� C circuit, the uncharged capacitor will be charged with the same potential of the battery and in this case, the current will be zero $i = 0$ For R 鈥� L circuit, the change on current in the inductor will be zero, while through the resistance it will be constant $i_{R} = \frac{emf}{R}$