A Best Way To Crack Gorenment Job Exams

ECE Objective Questions { Operational Amplifier and Its Applications }



92. One condition for oscillation is
A. a phase shift around the feedback loop of 180?
B. a gain around the feedback loop of one-third
C. a phase shift around the feedback loop of 0?
D. a gain around the feedback loop of less than 1

93.  A second condition for oscillations IS
A. a gain of 1 around the feedback loop
B. no gain around the feedback loop
C. the attenuation of the feedback circuit must be one-third
D. the feedback circuit must be capacitive

94. In a certain oscillator, A, = 50. The attenuation of the feedback circuit must be
A.1
B.0.01
C.10
D.0.02

95. For an oscillator to properly start, the gain around the feedback loop must initially be
A.1
B. greater than 1
C. less than 1
D. equal to attenuation of feedback circuit

96.  In a Wien-bridge oscillator, if the resistances in the positive feedback circuit are decreased, the frequency
A. remains the same
B. decreases
C. increases
D. insufficient data

97. In a Colpitt's oscillator, feedback is obtained
A. by magnetic induction
B. by a tickler coil
C. from the centre of split capacitors
D. none of the above

98. The Q of a crystal is of the order of
A.100
B.1000
C.50
D. more than 10,000

Page 14 of 29

« 12 13  14  1516 »

Subjects