07-12-2012, 12:11 PM
Objective Paper-II–2011
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1. Consider the following statements:
(1) A Schmitt trigger circuit can be emitter-coupled bi-stable circuit.
(2) Schmitt trigger circuit exhibits hysteresis phenomenon.
(3) The output of a Schmitt trigger will be triangular if the input is square wave.
Which of these statements are correct?
(A) 1, 2 and 3 (B) 1 and 2 only © 2 and 3 only (D) 1 and 3 only
2. In order to obtain repetitive pulses of unequal mark space durations one can use:
(1) A voltage comparator fed with a triangular wave signal and a dc voltage.
(2) An astable multi-vibrator
(3) A mono-stable multi-vibrator fed with a square wave input.
(A) 1 and 3 (B) 1 and 2 only © 2 and 3 only (D) 1, 2 and 3
3. A small signal voltage amplifier in common emitter configuration was working
satisfactorily. Suddenly its emitter-bypass capacitor ( E C ) got disconnected. Its:
(1) Voltage gain will decrease (2) Voltage gain will increase
(3) Bandwidth will decrease (4) Bandwidth will increase
(A) 1 and 4 only (B) 2 and 3 only © 3 and 4 only (D) 1,2, 3 and 4
4. A series resonant circuit has a resistance of 47 ohms, inductance of 2H and
capacitance of 2μF with a supply voltage of 10 volts. The current through the
circuit at resonance is:
(A) 0.833 amp (B) 0.212 amp © 0.196 amp (D) 0 amp
5. Once an SCR is turned on, it remains so until the anode current goes below:
(A) Trigger current (B) Break over current
© Threshold current (D) Holding current
6. In a PLL
(A) Capture range – Lock range ¹ Free running frequency
(B) Capture range – Lock range = Free running frequency
© Capture range > Lock range
(D) Capture range < Lock range
7. The main advantage of active filter is that it can be realized without using:
(A) Transistor (B) Capacitor © Resistor (D) Inductor