Resonance and Non-sinusoidal Waves
----------------------------------------------------------------------------------------------------------------------------------1.) One leg of a radio tuned circuit has a capacitance of 1 x 10-9 farad. It is tuned at 200 KHz, what is the
inductance of the other leg in Henry
a) 6.33 x 10-4
c) 8.25 x 10-5
-3
b) 20 x 10
d) 120 x 10-3
2.) The current in RLC series circuit ie., at resonance is
a) Maximum
c) Minimum
b) Zero
d) Infinity
3.) A coil having a resistance of 7Ω and an inductance of 0.01H is connected in series with a 75μF
capacitor across a voltage source of 220 volts. At what value of frequency the current will be
maximum?
a) 377 Hz
c) 60 Hz
b) 183.78 Hz
d) 512.45 Hz
4.) A filter in the form of a series L–R–C circuit is designed to operate at a resonant frequency of 5 kHz.
Included within the filter is a 20 mH inductance and 10 Ω resistance. Determine the bandwidth of the
filter
a) 76.9 Hz
c) 78.6 Hz
b) 79.6 Hz
d) 79.2 Hz
5.) A coil of negligible resistance and inductance 100 mH is connected in series with capacitance of 2 μF
and a resistance of 10 Ω across a 50 V, variable frequency supply. Determine the voltage
magnification at resonance
a) 23.36
c) 23.26
b) 22.63
d) 22.36.
6.) An R-L-C series circuit consists of a resistance of 1000 Ω, an inductance of 100mH and a
capacitance of 10 pF. If a voltage of 100 V is applied across the combination. Determine the half
power points
a) 158.2 & 159.8 KHz
c) 158.2 & 158.9 KHz
b) 152.8 & 159.8 KHz
d) 152.8 & 158.9 KHz
7.) A 100mH coil has an equivalent resistance of 15 ohms what parallel capacitance will cause
resonance at 60Hz frequency.
a) 70 micro-farad
c) 50 micro-farad
b) 60 micro-farad
d) 40 micro-farad
8.) An alternating current of rectangular wave shape has an amplitude of 20 and a frequency of 1 Hz.
What is the average current
a) 20
c) 10
b) 5
d) 2
9.) Given a sinusoidal voltage v(t) =200cos(377t + 30o) volts. What is the smallest positive value of t at
which the voltage v will be equal to zero?
a) 2.87 ms
c) 2.76 ms
b) 2.78 ms
d) 2.67 ms
10) A current is represented by its equation 10 sin(ωt + 30o) and 5 sin (ωt – 30o). the magnitudes of the
components are instantaneous values. What is the Rms value of the current?
a) 13.22 A
c) 1.1 A
b) 7.9 A
d) 10.6 A