4
MCQ (Single Correct Answer)
To reduce the resonant frequency in an $L-C-R$ series circuit with a generator
A
the generator frequency should be reduced
B
another capacitor should be added in parallel to the first
C
the iron core of the inductor should be removed
D
dielectric in the capacitor should be removed
5
MCQ (Single Correct Answer)
Which of the following combinations should be selected for better tuning of an $L-C-R$ circuit used for communication?
A
$R=20 \Omega, L=1.5 \mathrm{H}, C=35 \propto \mathrm{~F}$
B
$R=25 \Omega, L=2.5 \mathrm{H}, C=45 \alpha \mathrm{~F}$
C
$R=15 \Omega, L=3.5 \mathrm{H}, C=30 \alpha \mathrm{~F}$
D
$R=25 \Omega, L=1.5 \mathrm{H}, C=45 \propto \mathrm{~F}$
6
MCQ (Single Correct Answer)
An inductor of reactance $1 \Omega$ and a resistor of $2 \Omega$ are connected in series to the terminals of a 6 V (rms) AC source. The power dissipated in the circuit is
A
8 W
B
12 W
C
14.4 W
D
18 W
7
MCQ (Single Correct Answer)
The output of a step-down transformer is measured to be 24 V when connected to a 12 W light bulb. The value of the peak current is
A
$1 / \sqrt{2} \mathrm{~A}$
B
$\sqrt{2} \mathrm{~A}$
C
2 A
D
$2 \sqrt{2} \mathrm{~A}$
8
MCQ (Multiple Correct Answer)
As the frequency of an AC circuit increases, the current first increases and then decreases. What combination of circuit elements is most likely to comprise the circuit?
A
Inductor and capacitor
B
Resistor and inductor
C
Resistor and capacitor
D
Resistor, inductor and capacitor