HOMEWORK 11
1- In an oscillating LC circuit, L=5.0 mH and C=2.0 µF. At t=0 the charge in the
capacitor is zero and the current is 2.0 A. (a) What is the maximum charge that will
appear in the capacitor? (b) At what earliest time t>0 is the energy stored in the capacitor
greatest and what is that greatest energy? (c) What is the current in the circuit at that
time? (d) What is the frequency of the oscillatory charge?
2- A series RLC circuit has inductance L=10 mH, capacitance C=1.6 µF and resistance
R=1.5 Ω. (a) What is the frequency of oscillation of the current? (b) What is the charge
on the capacitor after 50 cycles? (c) Find the time required for the maximum energy
stored in the capacitor during one oscillation to fall to half its initial value.
3- A 10 mH inductor is connected to an ac generator with emf 30V cos(300 s-1 t). (a)
What is the maximum value of the current? (b) When the current is a maximum, what is
the emf of the generator? (c) When the emf is 12V and increasing in magnitude, what is
the current?
4- A 2.0 µF capacitor is connected to the same emf of problem 3. (a) What is the
amplitude of the resulting alternating current? (b) What is the maximum charge on the
capacitor?
5- The generator of problem 3 is connected in series to a RLC circuit having inductance
L=10 mH, capacitance C=1.6 µF and resistance R=1.5 Ω. Find (a) the capacitive
reactance XC, (b) the impedance Z, and (c) the current amplitude I. A second capacitor of
identical capacitance is then connected in series with the other components. Determine
whether the values of XC, Z or I will increase, decrease or remain unchanged.
6- A transformer has 60 primary turns and 500 secondary turns. If VP is 120 V, what is
the secondary voltage?