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WorksheetsElectronic Principles and Circuits
Total questions: 20
Worksheet time: 14mins
When a negative voltage feedback is applied to an amplifier ,its voltage gain
Is increased
Is reduced
Remains the same
None of the above
The value of negative feedback fraction is always
Less than 1
More than 1
Equal to 1
None of these
A feed back circuit usually employs (a) Network
The gain of an amplifier with feed back is known as (a) gain
When voltage feedback (negative) is applied to an amplifier, its input impedance
is decreased
is increased
remains the same
none of the above
When current feed back (negative ) ia applied to an amplifier ,its input impedance
is increased
is decreased
remains the same
none of the above
Negative feedback is employed in
(a)
If voltage gain without feed back and feedback fractions are Av and Mv respective then gain with negative voltage feedback is
AV/1-Av Mv
Av/1+Av Mv
1+Av Mv/Av
(1+Av Mv)Av
In the expression for voltage gain with negative voltage feedback the term 1+AmMv is known as
gain factor
feedback factor
sacrifice factor
none of the above
Feedback is an amplifier always helps to
Control its output
Increase its output
Decrease its input impedance
Stabilize its gain.
The term βa is called feedback
(a)
An oscillator produces _____oscillation
damped
undamped
modulated
none of these
An oscillator converts
a.c power into d.c power
d.c power into a.c power
mechanical power into a.c power
thermal mechanical power into a.c power
In an LC transistor oscillator, the active device is (a)
In a phase shift oscillator we use ___RC sections
2
3
4
5
A Wien bridge oscillator use ___feedback
only positive
only negative
both positive and negative
neither positive nor negative
Negative feedback is an amplifier
Lowers its lower 3dB frequency
Raises its upper 3 Db frequency
Increases its band-width
All of these
The shunt-derived series-fed feedback in an amplifier
Increases its output impedance
Decreases its output impedance
either Increase or decrease impedance
neither Increase nor decrease impedance
In a phase shift oscillator the frequency determining elements are
R
L
C
F
The crystal oscillator frequency is very stable due to ____ of the crystal
rigidity
vibrations
low Q
high Q
