Q. DC amplifiers have a tendency to be unstable.

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Q. A half wave diode rectifier has a capacitance input filter. If input voltage is Vm sin ωt, PIV is

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Q. An amplifier with loop gain Aβ will be more stable for value of Aβ as

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Q. A CB amplifier has re = 6 Ω, RL = 600 Ω and a = 0.98. The voltage gain is

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Q. A bridge rectifier circuit has input of 50 Hz frequency. The load resistance is RL and filter capacitance is C. For good output wave shape, the time constant RLC should be at least equal to

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Q. In class C operation of an amplifier circuit, the collector current exists for

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Q. In a BJT circuit a pnp transistor is replaced by npn transistor. To analyse the new circuit

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Q. To protect the diodes in a rectifier and capacitor input filter circuit it is necessary to use

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Q. Maximum efficiency of class B power amplifier is 50%.

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Q. The self bias provides

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Q. The efficiency of a full wave rectifier using centre tapped transformer is twice that in full wave bridge rectifier.

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Q. Assertion (A): CE amplifier is the most widely used BJT amplifier

Reason (R): CE amplifier has zero phase difference between input and output

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Q. Assertion (A): For large signal variations an amplifier circuit has to be analysed graphically

Reason (R): The output characteristics of a transistor is nonlinear.

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Q. Negative feedback reduces noise originating at the amplifier input.

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Q. An RC coupled amplifier has an open loop gain of 200 and a lower cutoff frequency of 50 Hz. If negative feedback with β = 0.1 is used, the lower cut off frequency will be

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Q. The load impedance ZL of a CE amplifier has R and L in series. The phase difference between output and input will be

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Q. If an amplifier with gain of - 1000 and feedback factor β = - 0.1 had a gain change of 20% due to temperature, the change in gain of the feedback amplifier would be

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Q. Which of the following power amplifiers has highest efficiency?

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Q. A full wave rectifier using centre tapped transformer and a bridge rectifier use similar diodes and have equal no load output voltage. Under equal load conditions

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Q. In an amplifier with a gain of - 1000 and feedback factor β = - 0.1, the change in gain is 20% due to temperature. The change in gain for feedback amplifier will be

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