Q7.1
A 100Ω
resistor is connected to a 220V
, 50Hz
ac supply.
a) What is the rms value of current in the circuit?
b) What is the net power consumed over a full cycle?
solutions
a) What is the rms value of current in the circuit?
b) What is the net power consumed over a full cycle?
solutions
Q7.2
a) The peak voltage of an ac supply is 300V
. What is the rms voltage?
b) The rms value of current in an ac circuit is 10A . What is the peak current?
solutions
b) The rms value of current in an ac circuit is 10A . What is the peak current?
solutions
Q7.3
A 44mH
inductor is connected to 220V
,50Hz
ac supply. Determine the rms value of the current in the circuit
solutions
solutions
Q7.4
A 60μF
capacitor is connected to a 110V
,60Hz
ac supply. Determine the rms value of the current in the circuit.
solutions
solutions
Q7.5
In exercises 4
and 5
What is the net power absorbed by each circuit over a complete cycle? Explain your answer.
solutions
solutions
Q7.6
Obtain the resonant frequency ωr
of a series LCR circuit with L=2.0H
, C=32μF
and R=10Ω
. What is the Q-value of this current?
solutions
solutions
Q7.7
A charged 30μF
capacitor is connected to a 27mH
inductor. What is the angular frequency of free oscillations of the circuit?
solutions
solutions
Q7.8
Suppose the initial charge on the capacitor in exercise 7
is 6mC
. What is the total energy stored in the circuit initially? What is the total energy at a later time?
solutions
solutions
Q7.9
A series LCR circuit with R=20Ω
, L=1.5H
and C=35μF
is connected to a variable frequency 200V
ac supply. When the frequency of the supply equals the natural frequency of the circuit, what is the average power transferred to the circuit in one complete cycle?
solutions
solutions
Q7.10
A radio can tune over the frequency range of a portion of MW
broadcast band: (800kHz
to 1200kHz
). If its LC circuit has an effective inductance of 200μH
, what must be the range of its variable capacitor?
(Hint: For tuning, the natural frequency i.e., the frequency of free oscillations of the LC circuit should be equal to the frequency of the radio wave.)
solutions
solutions
Q7.11
Figure shows a series LCR circuit connected to a variable frequency 230V
source. L=5.0H
, C=80μF
, R=40Ω
.
a) Determine the source frequency which drives the circuit in resonance.
b) Obtain the impedance of the circuit and the amplitude of current at the resonating frequency.
c) Determine the rms potential drops across the three elements of the circuit. Show that the potential drop across the LC combination is zero at the resonating frequency.
solutions
a) Determine the source frequency which drives the circuit in resonance.
b) Obtain the impedance of the circuit and the amplitude of current at the resonating frequency.
c) Determine the rms potential drops across the three elements of the circuit. Show that the potential drop across the LC combination is zero at the resonating frequency.
solutions