NET, IAS, State-SET (KSET, WBSET, MPSET, etc.), GATE, CUET, Olympiads etc.: Physics MCQs (Practice_Test 25 of 35)
Glide to success with Doorsteptutor material for competitive exams : get questions, notes, tests, video lectures and more- for all subjects of your exam.
- An electronic oscillator gives sustained oscillations when the feedback is
- negative and out of phase with the input
- negative and in phase with the input
- positive and, out of phase with. The input
- positive and in phase with the input
- A zener diode is also a p-n junction diode. It can be used as a/an
- half-wave rectifier
- full-wave rectifier
- ac voltage regulator
- dc voltage regulator
- A transistor is operated in CB mode. If the collector base voltage is reduced to zero keeping the input current undisturbed, the output will be
- zero
- a little higher than the input current
- equal to the input current
- a little less then the input current
- The circuit of a common emitter transistor amplifier with conventional stabilized bias is shown in the figure. In this circuit, R l and R 2
- as well as Re forward bias the base-emitter junction
- forward bias the base miter junction but Re reverse biases the base-emitter junction
- reverse bias the base-emitter junction but Re forward biases the base-emitter junction
- as well as Re reverse bias the base-emitter junction
- The overall gain of a two-stage amplifier is 80 dB, If the voltage gain of the, first stage is 100, then the voltage gain of the second stage is:
- Gain 20
- Gain 100
- Gain 180
- Gain 8000
- The equivalent electrical circuit of a vibrating crystal is as shown below: The expression for the resonance frequency of this circuit is
- Equi p-p LC
- Equi p-p L (C + Cm)
- Equi p-C + C m/LC Cm
- Equi p-R (C + Cm)