SP212/3321&5521
Chapter 30 - Worksheet #3
Question 1: (Checkpoint 30-6) The figure shows three circuits with identical batteries, inductors,
and resistors. Rank the circuits according to the current through the battery (a) just after the
switch is closed and (b) a long time later, greatest first.
Question 2: A series RL circuit is shown below. The switch is closed at time t=0. (a) How much
current is flowing through the circuit at time t=3.0 ms? (b) What is the magnitude of the induced
emf across the inductor at time t=3.0 ms? (c) How much potential energy is stored in the inductor
at time t=3.0 ms?
5.0 Ω
+
10.0 V
2.5 mH
−
SP212/3321&5521
Chapter 30 - Worksheet #3
Question 3: The switch in the series RL circuit below, with R=0.174 Ω, is closed at time t=0. The
current builds up to 75% of its maximum value at t=4.00 s What is L in this circuit?
0.174 Ω
L
E
Question 4: A solenoid wrapped with N =450 turns is 0.150 m long and has a cross-sectional area
of 8.50×10−4 m2 . A current of 3.25 A flows through the solenoid. (a) How much potential energy
is stored in the solenoid? (b) What is the energy density of the magnetic field inside the solenoid?